In this post, I will give a list of all undocumented parameters in Oracle 11g. Here is a query to see all the parameters (documented and undocumented) which contain the string you enter when prompted:
– Enter name of the parameter when prompted
SET linesize 235
col Parameter FOR a50
col SESSION FOR a28
col Instance FOR a55
col S FOR a1
col I FOR a1
col D FOR a1
col Description FOR a90
SELECT
a.ksppinm "Parameter",
decode(p.isses_modifiable,'FALSE',NULL,NULL,NULL,b.ksppstvl) "Session",
c.ksppstvl "Instance",
decode(p.isses_modifiable,'FALSE','F','TRUE','T') "S",
decode(p.issys_modifiable,'FALSE','F','TRUE','T','IMMEDIATE','I','DEFERRED','D') "I",
decode(p.isdefault,'FALSE','F','TRUE','T') "D",
a.ksppdesc "Description"
FROM x$ksppi a, x$ksppcv b, x$ksppsv c, v$parameter p
WHERE a.indx = b.indx AND a.indx = c.indx
AND p.name(+) = a.ksppinm
AND UPPER(a.ksppinm) LIKE UPPER('%&1%')
ORDER BY a.ksppinm;
Enter value for 1:
Here is the list of all undocumented parameters in Oracle 11g :
| PARAMETER NAME | PARAMETER VALUE | DESCRIPTION |
|---|---|---|
| _4031_dump_bitvec | 67194879 | bitvec to specify dumps prior to 4031 error |
| _4031_dump_interval | 300 | Dump 4031 error once for each n-second interval |
| _4031_max_dumps | 100 | Maximum number of 4031 dumps for this process |
| _4031_sga_dump_interval | 3600 | Dump 4031 SGA heapdump error once for each n-second interval |
| _4031_sga_max_dumps | 10 | Maximum number of SGA heapdumps |
| _NUMA_instance_mapping | Not specified | Set of nodes that this instance should run on |
| _NUMA_pool_size | Not specified | aggregate size in bytes of NUMA pool |
| _PX_use_large_pool | FALSE | Use Large Pool as source of PX buffers |
| _UTL_FILE_FOLLOW_SYMLINKS | FALSE | UTL_FILE backout event which allows UTL_FILE to open symlinks |
| __db_cache_size | 314572800 | Actual size of DEFAULT buffer pool for standard block size buffers |
| __dg_broker_service_names | pdb11_XPT | service names for broker use |
| __java_pool_size | 20971520 | Actual size in bytes of java pool |
| __large_pool_size | 4194304 | Actual size in bytes of large pool |
| __oracle_base | /u01/app/oracle | ORACLE_BASE |
| __pga_aggregate_target | 209715200 | Current target size for the aggregate PGA memory consumed |
| __sga_target | 629145600 | Actual size of SGA |
| __shared_io_pool_size | 0 | Actual size of shared IO pool |
| __shared_pool_size | 281018368 | Actual size in bytes of shared pool |
| __streams_pool_size | 0 | Actual size in bytes of streams pool |
| _abort_recovery_on_join | FALSE | if TRUE, abort recovery on join reconfigurations |
| _accept_versions | List of parameters for rolling operation | |
| _active_standby_fast_reconfiguration | TRUE | if TRUE optimize dlm reconfiguration for active/standby OPS |
| _adaptive_direct_read | TRUE | Adaptive Direct Read |
| _adaptive_fetch_enabled | TRUE | enable/disable adaptive fetch in parallel group by |
| _add_col_optim_enabled | TRUE | Allows new add column optimization |
| _add_stale_mv_to_dependency_list | TRUE | add stale mv to dependency list |
| _addm_auto_enable | TRUE | governs whether ADDM gets run automatically after every AWR snapshot |
| _addm_skiprules | comma-separated list of ADDM nodes to skip | |
| _addm_version_check | TRUE | governs whether ADDM checks the input AWR snapshot version |
| _adjust_literal_replacement | FALSE | If TRUE, we will adjust the SQL/PLUS output |
| _affinity_on | TRUE | enable/disable affinity at run time |
| _aiowait_timeouts | 100 | Number of aiowait timeouts before error is reported |
| _alert_expiration | 604800 | seconds before an alert message is moved to exception queue |
| _alert_message_cleanup | 1 | Enable Alert Message Cleanup |
| _alert_message_purge | 1 | Enable Alert Message Purge |
| _alert_post_background | 1 | Enable Background Alert Posting |
| _all_shared_dblinks | treat all dblinks as shared | |
| _allocate_creation_order | FALSE | should files be examined in creation order during allocation |
| _allocation_update_interval | 3 | interval at which successful search in L1 should be updated |
| _allow_commutativity | TRUE | allow for commutativity of +, * when comparing expressions |
| _allow_drop_snapshot_standby_grsp | FALSE | Allow dropping snapshot standby guaranteed restore point |
| _allow_error_simulation | FALSE | Allow error simulation for testing |
| _allow_level_without_connect_by | FALSE | allow level without connect by |
| _allow_read_only_corruption | FALSE | allow read-only open even if database is corrupt |
| _allow_resetlogs_corruption | FALSE | allow resetlogs even if it will cause corruption |
| _allow_sage_attr | TRUE | Allow checking Disk Group SAGE Attr |
| _allow_terminal_recovery_corruption | FALSE | Finish terminal recovery even if it may cause corruption |
| _alternate_iot_leaf_block_split_points | TRUE | enable alternate index-organized table leaf-block split-points |
| _always_anti_join | CHOOSE | always use this method for anti-join when possible |
| _always_semi_join | CHOOSE | always use this method for semi-join when possible |
| _always_star_transformation | FALSE | always favor use of star transformation |
| _app_ctx_vers | FALSE | enable app ctx versioning |
| _aq_tm_scanlimit | 0 | scan limit for Time Managers to clean up IOT |
| _arch_corrupted_redo_log | 0 | Variable to simulate corruption errors during archivals |
| _arch_io_slaves | 0 | ARCH I/O slaves |
| _array_update_vector_read_enabled | FALSE | Enable array update vector read |
| _ash_disk_filter_ratio | 10 | Ratio of the number of in-memory samples to the number of samples actually written to disk |
| _ash_disk_write_enable | TRUE | To enable or disable Active Session History flushing |
| _ash_dummy_test_param | 0 | Oracle internal dummy ASH parameter used ONLY for testing! |
| _ash_eflush_trigger | 66 | The percentage above which if the in-memory ASH is full the emergency flusher will be triggered |
| _ash_enable | TRUE | To enable or disable Active Session sampling and flushing |
| _ash_min_mmnl_dump | 90 | Minimum Time interval passed to consider MMNL Dump |
| _ash_sample_all | FALSE | To enable or disable sampling every connected session including ones waiting for idle waits |
| _ash_sampling_interval | 1000 | Time interval between two successive Active Session samples in millisecs |
| _ash_size | 1048618 | To set the size of the in-memory Active Session History buffers |
| _asm_acd_chunks | 1 | initial ACD chunks created |
| _asm_allow_only_raw_disks | TRUE | Discovery only raw devices |
| _asm_allow_resilver_corruption | FALSE | Enable disk resilvering for external redundancy |
| _asm_ausize | 1048576 | allocation unit size |
| _asm_blksize | 4096 | metadata block size |
| _asm_compatibility | 10.1 | default ASM compatibility level |
| _asm_dbmsdg_nohdrchk | FALSE | dbms_diskgroup.checkfile does not check block headers |
| _asm_disk_repair_time | 14400 | seconds to wait before dropping a failing disk |
| _asm_emulmax | 10000 | max number of concurrent disks to emulate I/O errors |
| _asm_emultimeout | 0 | timeout before emulation begins (in 3s ticks) |
| _asm_kfdpevent | 0 | KFDP event |
| _asm_kfioevent | 0 | KFIO event |
| _asm_libraries | ufs | library search order for discovery |
| _asm_maxio | 1048576 | Maximum size of individual I/O request |
| _asm_repairquantum | 60 | quantum (in 3s) used to compute elapsed time for disk drop |
| _asm_runtime_capability_volume_support | FALSE | runtime capability for volume support returns supported |
| _asm_skip_resize_check | FALSE | skip the checking of the clients for s/w compatibility for resize |
| _asm_stripesize | 131072 | ASM file stripe size |
| _asm_stripewidth | 8 | ASM file stripe width |
| _asm_wait_time | 18 | Max/imum time to wait before asmb exits |
| _asmlib_test | 0 | Osmlib test event |
| _asmsid | asm | ASM instance id |
| _assm_default | TRUE | ASSM default |
| _async_recovery_claims | TRUE | if TRUE, issue recovery claims asynchronously |
| _async_recovery_reads | TRUE | if TRUE, issue recovery reads asynchronously |
| _async_ts_threshold | 1 | check tablespace thresholds asynchronously |
| _auto_assign_cg_for_sessions | FALSE | auto assign CGs for sessions |
| _automatic_maintenance_test | 0 | Enable AUTOTASK Test Mode |
| _automemory_broker_interval | 3 | memory broker statistics gathering interval for auto memory |
| _autotask_max_window | 480 | Maximum Logical Maintenance Window Length in minutes |
| _autotask_min_window | 15 | Minimum Maintenance Window Length in minutes |
| _autotune_gtx_idle_time | 600 | idle time to trigger auto-shutdown a gtx background process |
| _autotune_gtx_interval | 5 | interval to autotune global transaction background processes |
| _autotune_gtx_threshold | 60 | auto-tune threshold for degree of global transaction concurrency |
| _avoid_prepare | TRUE | if TRUE, do not prepare a buffer when the master is local |
| _aw_row_source_enabled | TRUE | Enables AW Row Source instead of collection iterator |
| _awr_corrupt_mode | FALSE | AWR Corrupt Mode |
| _awr_disabled_flush_tables | Disable flushing of specified AWR tables | |
| _awr_flush_threshold_metrics | TRUE | Enable/Disable Flushing AWR Threshold Metrics |
| _awr_flush_workload_metrics | FALSE | Enable/Disable Flushing AWR Workload Metrics |
| _awr_mmon_cpuusage | TRUE | Enable/disable AWR MMON CPU Usage Tracking |
| _awr_restrict_mode | FALSE | AWR Restrict Mode |
| _awr_sql_child_limit | 200 | Setting for AWR SQL Child Limit |
| _b_tree_bitmap_plans | TRUE | enable the use of bitmap plans for tables even when the tables only have B-tree indexes |
| _backup_disk_io_slaves | 0 | BACKUP Disk I/O slaves |
| _backup_encrypt_opt_mode | 4294967294 | specifies encryption block optimization mode |
| _backup_io_pool_size | 1048576 | memory to reserve from the large pool |
| _backup_kgc_bufsz | 0 | specifies buffer size to be used by BZIP2 compression |
| _backup_kgc_memlevel | 8 | specifies memory level for ZLIB compression |
| _backup_kgc_niters | 0 | specifies number of iterations done by BZIP2 compression |
| _backup_kgc_perflevel | 1 | specifies compression (performance) level for ZLIB compression |
| _backup_kgc_scheme | ZLIB | specifies compression scheme |
| _backup_kgc_type | 0 | specifies compression type used by kgc BZIP2 compression |
| _backup_kgc_windowbits | 15 | specifies window size for ZLIB compression |
| _backup_ksfq_bufcnt | 0 | number of the ksfq buffers used for backup/restore |
| _backup_ksfq_bufcnt_max | 0 | maximum number of the ksfq buffer used for backup/restore |
| _backup_ksfq_bufsz | 0 | size of the ksfq buffer used for backup/restore |
| _backup_max_gap_size | 4294967294 | largest gap in an incremental/optimized backup buffer, in bytes |
| _bct_bitmaps_per_file | 8 | number of bitmaps to store for each datafile |
| _bct_buffer_allocation_max | 104857600 | maximum size of all change tracking buffer allocations, in bytes |
| _bct_buffer_allocation_min_extents | 1 | mininum number of extents to allocate per buffer allocation |
| _bct_buffer_allocation_size | 2097152 | size of one change tracking buffer allocation, in bytes |
| _bct_chunk_size | 0 | change tracking datafile chunk size, in bytes |
| _bct_crash_reserve_size | 262144 | change tracking reserved crash recovery SGA space, in bytes |
| _bct_file_block_size | 0 | block size of change tracking file, in bytes |
| _bct_file_extent_size | 0 | extent size of change tracking file, in bytes |
| _bct_fixtab_file | change tracking file for fixed tables | |
| _bct_initial_private_dba_buffer_size | 0 | initial number of entries in the private change tracking dba buffers |
| _bct_public_dba_buffer_size | 0 | total size of all public change tracking dba buffers, in bytes |
| _bitmap_or_improvement_enabled | TRUE | controls extensions to partition pruning for general predicates |
| _block_change_tracking | TRUE | change tracking possible |
| _blocking_sess_graph_cache_size | blocking session graph cache size in bytes | |
| _blocks_per_cache_server | 64 | number of consecutive blocks per global cache server |
| _bloom_filter_debug | 0 | debug level for bloom filtering |
| _bloom_filter_enabled | TRUE | enables or disables bloom filter |
| _bloom_predicate_enabled | FALSE | enables or disables bloom filter predicate pushdown |
| _bloom_pruning_enabled | TRUE | Enable partition pruning using bloom filtering |
| _bloom_vector_elements | 0 | number of elements in a bloom filter vector |
| _bsln_adaptive_thresholds_enabled | TRUE | Adaptive Thresholds Enabled |
| _bt_mmv_query_rewrite_enabled | TRUE | allow rewrites with multiple MVs and base tables |
| _buffer_busy_wait_timeout | 100 | buffer busy wait time in centiseconds |
| _buffered_publisher_flow_control_threshold | 0 | Flow control threshold for buffered publishers except capture |
| _bufq_stop_flow_control | FALSE | Stop enforcing flow control for buffered queues |
| _build_deferred_mv_skipping_mvlog_update | FALSE | DEFERRED MV creation skipping MV log setup update |
| _bump_highwater_mark_count | 0 | how many blocks should we allocate per free list on advancing HWM |
| _bwr_for_flushed_pi | TRUE | if TRUE, generate a BWR for a flushed PI |
| _cache_stats_monitor | FALSE | if TRUE, enable cache stats monitoring |
| _capture_buffer_size | 65536 | To set the size of the PGA I/O recording buffers |
| _capture_publisher_flow_control_threshold | 0 | Flow control threshold for capture publishers |
| _case_sensitive_logon | TRUE | case sensitive logon enabled |
| _cgs_reconfig_timeout | 1000 | CGS reconfiguration timeout interval |
| _cgs_send_timeout | 300 | CGS send timeout value |
| _cgs_tickets | 1000 | CGS messaging tickets |
| _check_block_after_checksum | TRUE | perform block check after checksum if both are turned on |
| _check_block_new_invariant_for_flashback | FALSE | check block new invariant for flashback |
| _check_ts_threshold | 0 | check tablespace thresholds |
| _cleanup_rollback_entries | 100 | no. of undo entries to apply per transaction cleanup |
| _client_result_cache_bypass | FALSE | bypass the client result cache |
| _close_cached_open_cursors | FALSE | close cursors cached by PL/SQL at each commit |
| _cluster_library | clss | cluster library selection |
| _clusterwide_global_transactions | TRUE | enable/disable clusterwide global transactions |
| _collapse_wait_history | FALSE | collapse wait history |
| _collect_undo_stats | TRUE | Collect Statistics v$undostat |
| _column_compression_factor | 0 | Column compression ratio |
| _column_elimination_off | FALSE | turn off predicate-only column elimination |
| _column_tracking_level | 1 | column usage tracking |
| _compilation_call_heap_extent_size | 16384 | Size of the compilation call heaps extents |
| _complex_view_merging | TRUE | enable complex view merging |
| _compression_above_cache | 0 | number of recompression above cache for sanity check |
| _compression_advisor | 0 | Compression advisor |
| _compression_chain | 50 | percentage of chained rows allowed for Compression |
| _controlfile_block_size | 0 | control file block size in bytes |
| _controlfile_enqueue_dump | FALSE | dump the system states after controlfile enqueue timeout |
| _controlfile_enqueue_holding_time | 780 | control file enqueue max holding time in seconds |
| _controlfile_enqueue_timeout | 900 | control file enqueue timeout in seconds |
| _controlfile_section_init_size | control file initial section size | |
| _controlfile_section_max_expand | control file max expansion rate | |
| _controlfile_update_check | OFF | controlfile update sanity check |
| _convert_set_to_join | FALSE | enables conversion of set operator to join |
| _coord_message_buffer | 0 | parallel recovery coordinator side extra message buffer size |
| _corrupted_rollback_segments | corrupted undo segment list | |
| _cost_equality_semi_join | TRUE | enables costing of equality semi-join |
| _cp_num_hash_latches | 1 | connection pool number of hash latches |
| _cpu_to_io | 0 | divisor for converting CPU cost to I/O cost |
| _cr_grant_global_role | TRUE | if TRUE, grant lock for CR requests when block is in global role |
| _cr_grant_local_role | AUTO | turn 3-way CR grants off, make it automatic, or turn it on |
| _cr_server_log_flush | TRUE | if TRUE, flush redo log before serving a CR buffer |
| _cursor_bind_capture_area_size | 400 | maximum size of the cursor bind capture area |
| _cursor_bind_capture_interval | 900 | interval (in seconds) between two bind capture for a cursor |
| _cursor_db_buffers_pinned | 178 | additional number of buffers a cursor can pin at once |
| _cursor_features_enabled | 2 | Shared cursor features enabled bits. |
| _cursor_plan_enabled | TRUE | enable collection and display of cursor plans |
| _cursor_plan_hash_version | 1 | version of cursor plan hash value |
| _cursor_plan_unparse_enabled | TRUE | enables/disables using unparse to build projection/predicates |
| _cursor_stats_bucket | 15 | Hash table buckets for cursor stats (2^). |
| _cursor_stats_heap | 4 | Heaps/latches for cursor stats. |
| _cvw_enable_weak_checking | TRUE | enable weak view checking |
| _db_aging_cool_count | 1 | Touch count set when buffer cooled |
| _db_aging_freeze_cr | FALSE | Make CR buffers always be too cold to keep in cache |
| _db_aging_hot_criteria | 2 | Touch count which sends a buffer to head of replacement list |
| _db_aging_stay_count | 0 | Touch count set when buffer moved to head of replacement list |
| _db_aging_touch_time | 3 | Touch count which sends a buffer to head of replacement list |
| _db_always_check_system_ts | TRUE | Always perform block check and checksum for System tablespace |
| _db_block_adjcheck | TRUE | adjacent cache buffer checks – low blkchk overwrite parameter |
| _db_block_adjchk_level | 0 | adjacent cache buffer check level |
| _db_block_align_direct_read | TRUE | Align Direct Reads |
| _db_block_bad_write_check | FALSE | enable bad write checks |
| _db_block_buffers | 27060 | Number of database blocks cached in memory: hidden parameter |
| _db_block_cache_clone | FALSE | Always clone data blocks on get (for debugging) |
| _db_block_cache_history | 0 | buffer header tracing (non-zero only when debugging) |
| _db_block_cache_history_level | 2 | buffer header tracing level |
| _db_block_cache_num_umap | 0 | number of unmapped buffers (for tracking swap calls on blocks) |
| _db_block_cache_protect | FALSE | protect database blocks (true only when debugging) |
| _db_block_cache_protect_internal | 0 | protect database blocks (for strictly internal use only) |
| _db_block_check_for_debug | FALSE | Check more and dump block before image for debugging |
| _db_block_check_objtyp | TRUE | check objd and typ on cache disk read |
| _db_block_corruption_recovery_threshold | 5 | threshold number of block recovery attempts |
| _db_block_do_full_mbreads | FALSE | do full block read even if some blocks are in cache |
| _db_block_hash_buckets | 65536 | Number of database block hash buckets |
| _db_block_hash_latches | 2048 | Number of database block hash latches |
| _db_block_header_guard_level | 0 | number of extra buffer headers to use as guard pages |
| _db_block_hi_priority_batch_size | 0 | Fraction of writes for high priority reasons |
| _db_block_known_clean_pct | 2 | Initial Percentage of buffers to maintain known clean |
| _db_block_lru_latches | 8 | number of lru latches |
| _db_block_max_cr_dba | 6 | Maximum Allowed Number of CR buffers per dba |
| _db_block_max_scan_pct | 40 | Percentage of buffers to inspect when looking for free |
| _db_block_med_priority_batch_size | 0 | Fraction of writes for medium priority reasons |
| _db_block_numa | 1 | Number of NUMA nodes |
| _db_block_prefetch_fast_longjumps_enabled | TRUE | Batched IO enable fast longjumps |
| _db_block_prefetch_limit | 0 | Prefetch limit in blocks |
| _db_block_prefetch_override | 0 | Prefetch force override in blocks |
| _db_block_prefetch_private_cache_enabled | TRUE | Batched IO enable private cache |
| _db_block_prefetch_quota | 10 | Prefetch quota as a percent of cache size |
| _db_block_prefetch_skip_reading_enabled | TRUE | Batched IO enable skip reading buffers |
| _db_block_table_scan_buffer_size | 4194304 | Size of shared table scan read buffer |
| _db_block_temp_redo | FALSE | generate redo for temp blocks |
| _db_block_trace_protect | FALSE | trace buffer protect calls |
| _db_block_vlm_check | FALSE | check of rvlm mapping leaks (for debugging) |
| _db_block_vlm_leak_threshold | 3 | Threshold for allowable vlm leaks |
| _db_blocks_per_hash_latch | Number of blocks per hash latch | |
| _db_cache_advice_batch_size | 128 | cache advisory simulation batch size |
| _db_cache_advice_sample_factor | 4 | cache advisory sampling factor |
| _db_cache_crx_check | FALSE | check for costly crx examination functions |
| _db_cache_pre_warm | TRUE | Buffer Cache Pre-Warm Enabled : hidden parameter |
| _db_cache_process_cr_pin_max | maximum number of cr pins a process may have | |
| _db_change_notification_enable | TRUE | enable db change notification |
| _db_disable_temp_encryption | FALSE | Diable Temp Encryption for Spills |
| _db_fast_obj_check | FALSE | enable fast object drop sanity check |
| _db_fast_obj_ckpt | TRUE | enable fast object checkpoint |
| _db_fast_obj_truncate | TRUE | enable fast object truncate |
| _db_file_direct_io_count | 1048576 | Sequential I/O buf size |
| _db_file_exec_read_count | 128 | multiblock read count for regular clients |
| _db_file_format_io_buffers | 4 | Block formatting I/O buf count |
| _db_file_noncontig_mblock_read_count | 11 | number of noncontiguous db blocks to be prefetched |
| _db_file_optimizer_read_count | 8 | multiblock read count for regular clients |
| _db_handles | 750 | System-wide simultaneous buffer operations |
| _db_handles_cached | 5 | Buffer handles cached each process |
| _db_hot_block_tracking | FALSE | track hot blocks for hash latch contention |
| _db_index_block_checking | TRUE | index block checking override parameter |
| _db_large_dirty_queue | 25 | Number of buffers which force dirty queue to be written |
| _db_lost_write_checking | FALSE | Enable scn based lost write detection mechanism |
| _db_mttr_advice | ON | MTTR advisory |
| _db_mttr_partitions | 0 | number of partitions for MTTR advisory |
| _db_mttr_sample_factor | 64 | MTTR simulation sampling factor |
| _db_mttr_sim_target | MTTR simulation targets | |
| _db_mttr_sim_trace_size | 256 | MTTR simulation trace size |
| _db_mttr_trace_to_alert | FALSE | dump trace entries to alert file |
| _db_noarch_disble_optim | FALSE | Image redo logging (NOARCHIVEMODE) |
| _db_num_evict_waitevents | 64 | number of evict wait events |
| _db_obj_enable_ksr | TRUE | enable ksr in object checkpoint/reuse |
| _db_percent_hot_default | 50 | Percent of default buffer pool considered hot |
| _db_percent_hot_keep | 0 | Percent of keep buffer pool considered hot |
| _db_percent_hot_recycle | 0 | Percent of recycle buffer pool considered hot |
| _db_percpu_create_cachesize | 2 | size of cache created per cpu in deferred cache create |
| _db_recovery_temporal_file_dest | default database recovery temporal file location | |
| _db_required_percent_fairshare_usage | 10 | percent of fairshare a processor group should always use |
| _db_row_overlap_checking | TRUE | row overlap checking override parameter for data/index blocks |
| _db_todefer_cache_create | TRUE | buffer cache deferred create |
| _db_writer_chunk_writes | 0 | Number of writes DBWR should wait for |
| _db_writer_coalesce_area_size | 2293760 | Size of memory allocated to dbwriter for coalescing writes |
| _db_writer_coalesce_write_limit | 131072 | Limit on size of coalesced write |
| _db_writer_flush_imu | TRUE | If FALSE, DBWR will not downgrade IMU txns for AGING |
| _db_writer_histogram_statistics | FALSE | maintain dbwr histogram statistics in x$kcbbhs |
| _db_writer_max_writes | 0 | Max number of outstanding DB Writer IOs |
| _db_writer_nomemcopy_coalesce | FALSE | Enable DBWR no-memcopy coalescing |
| _db_writer_verify_writes | FALSE | Enable lost write detection mechanism |
| _dbg_proc_startup | FALSE | debug process startup |
| _dbms_sql_security_level | 1 | Security level in DBMS_SQL |
| _dbwr_async_io | TRUE | Enable dbwriter asynchronous writes |
| _dbwr_scan_interval | 300 | dbwriter scan interval |
| _dbwr_tracing | 0 | Enable dbwriter tracing |
| _dde_flood_control_init | TRUE | Initialize Flood Control at database open |
| _dead_process_scan_interval | 60 | PMON dead process scan interval |
| _deadlock_diagnostic_level | 2 | automatic deadlock resolution diagnostics level |
| _deadlock_resolution_incidents_enabled | TRUE | create incidents during deadlock resolution |
| _deadlock_resolution_level | 1 | automatic deadlock resolution level |
| _deadlock_resolution_min_wait_timeout_secs | 60 | the minimum wait timeout required for deadlock resolution |
| _deadlock_resolution_signal_process_thresh_secs | 60 | the amount of time given to process a deadlock resolution signal |
| _dedicated_server_poll_count | 10 | dedicated server poll count |
| _dedicated_server_post_wait | FALSE | dedicated server post/wait |
| _dedicated_server_post_wait_call | FALSE | dedicated server post/wait call |
| _default_encrypt_alg | 0 | default encryption algorithm |
| _default_non_equality_sel_check | TRUE | sanity check on default selectivity for like/range predicate |
| _defer_log_boundary_ckpt | TRUE | defer media recovery checkpoint at log boundary |
| _defer_log_count | 2 | Number of log boundaries media recovery checkpoint lags behind |
| _delay_index_maintain | TRUE | delays index maintenance until after MV is refreshed |
| _desired_readmem_rate | 70 | The desired percentage of redo reading from memory |
| _diag_adr_auto_purge | TRUE | Enable/disable ADR MMON Auto Purging |
| _diag_adr_enabled | TRUE | Parameter to enable/disable Diag ADR |
| _diag_adr_test_param | 0 | Test parameter for Diagnosability |
| _diag_backward_compat | TRUE | Backward Compatibility for Diagnosability |
| _diag_cc_enabled | TRUE | Parameter to enable/disable Diag Call Context |
| _diag_conf_cap_enabled | TRUE | Parameter to enable/disable Diag Configuration Capture |
| _diag_daemon | TRUE | start DIAG daemon |
| _diag_dde_async_age_limit | 300 | diag dde async actions: message age limit (in seconds) |
| _diag_dde_async_cputime_limit | 300 | diag dde async actions: action cputime limit (in seconds) |
| _diag_dde_async_mode | 1 | diag dde async actions: dispatch mode |
| _diag_dde_async_msg_capacity | 1024 | diag dde async actions: message buffer capacity |
| _diag_dde_async_msgs | 50 | diag dde async actions: number of preallocated message buffers |
| _diag_dde_async_process_rate | 5 | diag dde async actions: message processing rate – per loop |
| _diag_dde_async_runtime_limit | 900 | diag dde async actions: action runtime limit (in seconds) |
| _diag_dde_async_slaves | 5 | diag dde async actions: max number of concurrent slave processes |
| _diag_dde_enabled | TRUE | enable DDE handling of critical errors |
| _diag_dde_fc_enabled | TRUE | Parameter to enable/disable Diag Flood Control |
| _diag_dde_fc_implicit_time | 0 | Override Implicit Error Flood Control time parameter |
| _diag_dde_fc_macro_time | 0 | Override Macro Error Flood Control time parameter |
| _diag_dde_inc_proc_delay | 1 | The minimum delay between two MMON incident sweeps (minutes) |
| _diag_diagnostics | TRUE | Turn off diag diagnostics |
| _diag_dump_timeout | 30 | timeout parameter for SYNC dump |
| _diag_hm_rc_enabled | TRUE | Parameter to enable/disable Diag HM Reactive Checks |
| _diag_hm_tc_enabled | FALSE | Parameter to enable/disable Diag HM Test(dummy) Checks |
| _diag_uts_control | 0 | UTS control parameter |
| _dimension_skip_null | TRUE | control dimension skip when null feature |
| _direct_path_insert_features | 0 | disable direct path insert features |
| _disable_12751 | FALSE | disable policy timeout error (ORA-12751) |
| _disable_adaptive_shrunk_aggregation | FALSE | adaptive shrunk aggregation |
| _disable_autotune_gtx | FALSE | disable autotune global transaction background processes |
| _disable_datalayer_sampling | FALSE | disable datalayer sampling |
| _disable_duplex_link | TRUE | Turn off connection duplexing |
| _disable_fast_aggregation | FALSE | fast aggregation |
| _disable_fast_validate | FALSE | disable PL/SQL fast validation |
| _disable_fastopen | FALSE | Do Not Use Fastopen |
| _disable_fba_qrw | 0 | disable flashback archiver query rewrite |
| _disable_fba_wpr | 0 | disable flashback archiver wait for prepared transactions |
| _disable_file_locks | FALSE | disable file locks for control, data, redo log files |
| _disable_flashback_archiver | 0 | disable flashback archiver |
| _disable_flashback_wait_callback | FALSE | Disable flashback wait callback |
| _disable_function_based_index | FALSE | disable function-based index matching |
| _disable_health_check | FALSE | Disable Health Check |
| _disable_highres_ticks | FALSE | disable high-res tick counter |
| _disable_image_check | FALSE | Disable Oracle executable image checking |
| _disable_incremental_checkpoints | FALSE | Disable incremental checkpoints for thread recovery |
| _disable_incremental_recovery_ckpt | FALSE | Disable incremental recovery checkpoint mechanism |
| _disable_index_block_prefetching | FALSE | disable index block prefetching |
| _disable_instance_params_check | FALSE | disable instance type check for ksp |
| _disable_interface_checking | FALSE | disable interface checking at startup |
| _disable_kcb_flashback_blocknew_opt | FALSE | Disable KCB flashback block new optimization |
| _disable_kcbhxor_osd | FALSE | disable kcbh(c)xor OSD functionality |
| _disable_kcbl_flashback_blocknew_opt | FALSE | Disable KCBL flashback block new optimization |
| _disable_latch_free_SCN_writes_via_32cas | FALSE | disable latch-free SCN writes using 32-bit compare & swap |
| _disable_latch_free_SCN_writes_via_64cas | FALSE | disable latch-free SCN writes using 64-bit compare & swap |
| _disable_logging | FALSE | Disable logging |
| _disable_metrics_group | 0 | Disable Metrics Group (or all Metrics Groups) |
| _disable_multiple_block_sizes | FALSE | disable multiple block size support (for debugging) |
| _disable_odm | FALSE | disable odm feature |
| _disable_parallel_conventional_load | FALSE | Disable parallel conventional loads |
| _disable_read_only_open_dict_check | FALSE | Disable read-only open dictionary check |
| _disable_rebalance_space_check | FALSE | disable space usage checks for storage reconfiguration |
| _disable_recoverable_recovery | FALSE | Disable the new recoverable recovery mechanism |
| _disable_recovery_read_skip | FALSE | Disable the read optimization during media recovery |
| _disable_sample_io_optim | FALSE | disable row sampling IO optimization |
| _disable_savepoint_reset | FALSE | disable the fix for bug 1402161 |
| _disable_sec_ticks | FALSE | disable low-res (sec) counter |
| _disable_selftune_checkpointing | FALSE | Disable self-tune checkpointing |
| _disable_streams_pool_auto_tuning | FALSE | disable streams pool auto tuning |
| _disable_sun_rsm | TRUE | Disable IPC OSD support for Sun RSMAPI |
| _disable_system_state | 4294967294 | disable system state dump |
| _disable_thread_internal_disable | FALSE | Disable thread internal disable feature |
| _disable_txn_alert | 0 | disable txn layer alert |
| _disable_vktm | FALSE | disable vktm process |
| _disable_wait_stack | FALSE | Disable wait stack |
| _discrete_transactions_enabled | FALSE | enable OLTP mode |
| _diskmon_pipe_name | DiSKMon skgznp pipe name | |
| _dispatcher_rate_scale | scale to display rate statistic (100ths of a second) | |
| _dispatcher_rate_ttl | time-to-live for rate statistic (100ths of a second) | |
| _distinct_view_unnesting | FALSE | enables unnesting of in subquery into distinct view |
| _distributed_recovery_connection_hold_time | 200 | number of seconds RECO holds outbound connections open |
| _dlmtrace | Trace string of global enqueue type(s) | |
| _dm_max_shared_pool_pct | 1 | max percentage of the shared pool to use for a mining model |
| _dml_monitoring_enabled | TRUE | enable modification monitoring |
| _domain_index_batch_size | 2000 | maximum number of rows from one call to domain index fetch routine |
| _domain_index_dml_batch_size | 200 | maximum number of rows for one call to domain index dml routines |
| _dra_bmr_number_threshold | 1000 | Maximum number of BMRs that can be done to a file |
| _dra_bmr_percent_threshold | 10 | Maximum percentage of blocks in a file that can be BMR-ed |
| _dra_enable_offline_dictionary | TRUE | Enable the periodic creation of the offline dictionary for DRA |
| _drop_table_granule | 256 | drop_table_granule |
| _drop_table_optimization_enabled | TRUE | reduce SGA memory use during drop of a partitioned table |
| _ds_iocount_iosize | 6553664 | Dynamic Sampling Service defaults: #IOs and IO Size |
| _dss_cache_flush | FALSE | enable full cache flush for parallel execution |
| _dtree_area_size | 131072 | size of Decision Tree Classification work area |
| _dtree_binning_enabled | TRUE | Decision Tree Binning Enabled |
| _dtree_bintest_id | 0 | Decision Tree Binning Test ID |
| _dtree_compressbmp_enabled | TRUE | Decision Tree Using Compressed Bitmaps Enabled |
| _dtree_max_surrogates | 1 | maximum number of surrogates |
| _dtree_pruning_enabled | TRUE | Decision Tree Pruning Enabled |
| _dummy_instance | FALSE | dummy instance started by RMAN |
| _dump_common_subexpressions | FALSE | dump common subexpressions |
| _dump_connect_by_loop_data | FALSE | dump connect by loop error message into trc file |
| _dump_cursor_heap_sizes | FALSE | dump comp/exec heap sizes to tryace file |
| _dump_interval_limit | 120 | trace dump time interval limit (in seconds) |
| _dump_max_limit | 5 | max number of dump within dump interval |
| _dump_qbc_tree | 0 | dump top level query parse tree to trace |
| _dump_rcvr_ipc | TRUE | if TRUE enables IPC dump at instance eviction time |
| _dump_system_state_scope | local | scope of sysstate dump during instance termination |
| _dump_trace_scope | global | scope of trace dump during a process crash |
| _dynamic_rls_policies | TRUE | rls policies are dynamic |
| _dynamic_stats_threshold | 30 | delay threshold (in seconds) between sending statistics messages |
| _edition_based_redefinition | FALSE | enable edition based redefinition |
| _eliminate_common_subexpr | TRUE | enables elimination of common sub-expressions |
| _emon_regular_ntfn_slaves | 4 | number of EMON slaves doing regular database notifications |
| _enable_NUMA_optimization | TRUE | Enable NUMA specific optimizations |
| _enable_automatic_maintenance | 1 | if 1, Automated Maintenance Is Enabled |
| _enable_automatic_sqltune | TRUE | Automatic SQL Tuning Advisory enabled parameter |
| _enable_block_level_transaction_recovery | TRUE | enable block level recovery |
| _enable_cscn_caching | FALSE | enable commit SCN caching for all transactions |
| _enable_ddl_wait_lock | TRUE | use this to turn off ddls with wait semantics |
| _enable_default_affinity | 0 | to enable default implementation of affinity osds |
| _enable_dml_lock_escalation | TRUE | enable dml lock escalation against partitioned tables if TRUE |
| _enable_exchange_validation_using_check | TRUE | use check constraints on the table for validation |
| _enable_fast_ref_after_mv_tbs | FALSE | enable fast refresh after move tablespace |
| _enable_hash_overflow | FALSE | TRUE – enable hash cluster overflow based on SIZE |
| _enable_hwm_sync | TRUE | enable HWM synchronization |
| _enable_list_io | FALSE | Enable List I/O |
| _enable_midtier_affinity | TRUE | enable midtier affinity metrics processing |
| _enable_nativenet_tcpip | FALSE | Enable skgxp driver usage for native net |
| _enable_obj_queues | TRUE | enable object queues |
| _enable_online_index_without_s_locking | TRUE | Allow online index creation algorithm without S DML lock |
| _enable_query_rewrite_on_remote_objs | TRUE | mv rewrite on remote table/view |
| _enable_refresh_schedule | TRUE | enable or disable MV refresh scheduling (revert to 9.2 behavior) |
| _enable_reliable_latch_waits | TRUE | Enable reliable latch waits |
| _enable_rlb | TRUE | enable RLB metrics processing |
| _enable_row_shipping | TRUE | use the row shipping optimization for wide table selects |
| _enable_scn_wait_interface | TRUE | use this to turn off scn wait interface in kta |
| _enable_separable_transactions | FALSE | enable/disable separable transactions |
| _enable_shared_pool_durations | TRUE | temporary to disable/enable kgh policy |
| _enable_shared_server_vector_io | FALSE | Enable shared server vector I/O |
| _enable_space_preallocation | 3 | enable space pre-allocation |
| _enable_spacebg | TRUE | enable space management background task |
| _enable_tablespace_alerts | TRUE | enable tablespace alerts |
| _enable_type_dep_selectivity | TRUE | enable type dependent selectivity estimates |
| _endprot_chunk_comment | chk 10235 dflt | chunk comment for selective overrun protection |
| _endprot_heap_comment | hp 10235 dflt | heap comment for selective overrun protection |
| _endprot_subheaps | TRUE | selective overrun protection for subeheaps |
| _enqueue_deadlock_time_sec | 5 | requests with timeout <= this will not have deadlock detection |
| _enqueue_debug_multi_instance | FALSE | debug enqueue multi instance |
| _enqueue_hash | 375 | enqueue hash table length |
| _enqueue_hash_chain_latches | 1 | enqueue hash chain latches |
| _enqueue_locks | 2260 | locks for managed enqueues |
| _enqueue_resources | 968 | resources for enqueues |
| _evolve_plan_baseline_report_level | TYPICAL | Level of detail to show in plan verification/evolution report |
| _evt_system_event_propagation | TRUE | disable system event propagation |
| _expand_aggregates | TRUE | expand aggregates |
| _explain_rewrite_mode | FALSE | allow additional messages to be generated during explain rewrite |
| _extended_pruning_enabled | TRUE | do runtime pruning in iterator if set to TRUE |
| _fair_remote_cvt | FALSE | if TRUE enables fair remote convert |
| _fairness_threshold | 4 | number of times to CR serve before downgrading lock |
| _fast_dual_enabled | TRUE | enable/disable fast dual |
| _fast_full_scan_enabled | TRUE | enable/disable index fast full scan |
| _fastpin_enable | 1 | enable reference count based fast pins |
| _fbda_busy_percentage | 0 | flashback archiver busy percentage |
| _fbda_inline2_percentage | 0 | flashback archiver full inline percentage |
| _fbda_inline_percentage | 0 | flashback archiver inline percentage |
| _fg_iorm_slaves | 1 | ForeGround I/O slaves for IORM |
| _fg_log_checksum | TRUE | Checksum redo in foreground process |
| _fic_algorithm_set | automatic | Set Frequent Itemset Counting Algorithm |
| _fic_area_size | 131072 | size of Frequent Itemset Counting work area |
| _fic_max_length | 20 | Frequent Itemset Counting Maximum Itemset Length |
| _fic_min_bmsize | 1024 | Frequent Itemset Counting Minimum BITMAP Size |
| _fic_outofmem_candidates | FALSE | Frequent Itemset Counting Out Of Memory Candidates Generation |
| _fifth_spare_parameter | fifth spare parameter – string | |
| _filemap_dir | FILEMAP directory | |
| _first_k_rows_dynamic_proration | TRUE | enable the use of dynamic proration of join cardinalities |
| _first_spare_parameter | first spare parameter – integer | |
| _fix_control | bug fix control parameter | |
| _flashback_allow_noarchivelog | FALSE | Allow enabling flashback on noarchivelog database |
| _flashback_archiver_partition_size | 0 | flashback archiver table partition size |
| _flashback_barrier_interval | 1800 | Flashback barrier interval in seconds |
| _flashback_copy_latches | 10 | Number of flashback copy latches |
| _flashback_format_chunk_mb | 4 | Chunk mega-bytes for formatting flashback logs using sync write |
| _flashback_format_chunk_mb_dwrite | 16 | Chunk mega-bytes for formatting flashback logs using delayed write |
| _flashback_fuzzy_barrier | TRUE | Use flashback fuzzy barrier |
| _flashback_generation_buffer_size | 4194304 | flashback generation buffer size |
| _flashback_hint_barrier_percent | 20 | Flashback hint barrier percent |
| _flashback_log_io_error_behavior | 0 | Specify Flashback log I/O error behavior |
| _flashback_log_min_size | 100 | Minimum flashback log size |
| _flashback_log_size | 1000 | Flashback log size |
| _flashback_logfile_enqueue_timeout | 600 | flashback logfile enqueue timeout for opens |
| _flashback_marker_cache_enabled | TRUE | Enable flashback database marker cache |
| _flashback_marker_cache_size | 328 | Size of flashback database marker cache |
| _flashback_max_log_size | 0 | Maximum flashback log size in bytes (OS limit) |
| _flashback_max_n_log_per_thread | 2048 | Maximum number of flashback logs per flashback thread |
| _flashback_max_standby_sync_span | 900 | Maximum time span between standby recovery sync for flashback |
| _flashback_n_log_per_thread | 128 | Desired number of flashback logs per flashback thread |
| _flashback_standby_barrier_interval | 1800 | Flashback standby barrier interval in seconds |
| _flashback_verbose_info | FALSE | Print verbose information about flashback database |
| _flashback_write_max_loop_limit | 10 | Flashback writer loop limit before it returns |
| _force_datefold_trunc | FALSE | force use of trunc for datefolding rewrite |
| _force_hsc_compress | FALSE | compress all new created tables |
| _force_oltp_compress | FALSE | OLTP Compress all new created tables |
| _force_rewrite_enable | FALSE | control new query rewrite features |
| _force_slave_mapping_intra_part_loads | FALSE | Force slave mapping for intra partition loads |
| _force_temptables_for_gsets | FALSE | executes concatenation of rollups using temp tables |
| _force_tmp_segment_loads | FALSE | Force tmp segment loads |
| _forwarded_2pc_threshold | 10 | auto-tune threshold for two-phase commit rate across RAC instances |
| _fourth_spare_parameter | fourth spare parameter – string | |
| _full_pwise_join_enabled | TRUE | enable full partition-wise join when TRUE |
| _gby_hash_aggregation_enabled | TRUE | enable group-by and aggregation using hash scheme |
| _gby_onekey_enabled | TRUE | enable use of one comparison of all group by keys |
| _gc_affinity_locking | TRUE | if TRUE, enable object affinity |
| _gc_affinity_locks | TRUE | if TRUE, get affinity locks |
| _gc_affinity_ratio | 50 | dynamic object affinity ratio |
| _gc_async_memcpy | FALSE | if TRUE, use async memcpy |
| _gc_bypass_readers | TRUE | if TRUE, modifications bypass readers |
| _gc_check_bscn | TRUE | if TRUE, check for stale blocks |
| _gc_coalesce_recovery_reads | TRUE | if TRUE, coalesce recovery reads |
| _gc_defer_time | 3 | how long to defer down converts for hot buffers |
| _gc_dissolve_undo_affinity | FALSE | if TRUE, dissolve undo affinity after an offline |
| _gc_element_percent | 110 | global cache element percent |
| _gc_global_checkpoint_scn | TRUE | if TRUE, enable global checkpoint scn |
| _gc_global_lru | AUTO | turn global lru off, make it automatic, or turn it on |
| _gc_initiate_undo_affinity | TRUE | if TRUE, initiate undo affinity after an online |
| _gc_integrity_checks | 1 | set the integrity check level |
| _gc_keep_recovery_buffers | TRUE | if TRUE, make recovery buffers current |
| _gc_latches | 8 | number of latches per LMS process |
| _gc_long_query_threshold | 0 | threshold for long running query |
| _gc_maximum_bids | 0 | maximum number of bids which can be prepared |
| _gc_policy_minimum | 1500 | dynamic object policy minimum activity per minute |
| _gc_policy_time | 10 | how often to make object policy decisions in minutes |
| _gc_read_mostly_locking | TRUE | if TRUE, enable read-mostly locking |
| _gc_statistics | TRUE | if TRUE, kcl statistics are maintained |
| _gc_transfer_ratio | 2 | dynamic object read-mostly transfer ratio |
| _gc_undo_affinity | TRUE | if TRUE, enable dynamic undo affinity |
| _gc_undo_block_disk_reads | TRUE | if TRUE, enable undo block disk reads |
| _gc_use_cr | TRUE | if TRUE, allow CR pins on PI and WRITING buffers |
| _gc_vector_read | TRUE | if TRUE, vector read current buffers |
| _gc_voluntary_down_convert_obj | 0 | object number for voluntary down-convert |
| _gcs_fast_reconfig | TRUE | if TRUE, enable fast reconfiguration for gcs locks |
| _gcs_latches | 0 | number of gcs resource hash latches to be allocated per LMS process |
| _gcs_process_in_recovery | TRUE | if TRUE, process gcs requests during instance recovery |
| _gcs_res_per_bucket | 16 | number of gcs resource per hash bucket |
| _gcs_resources | number of gcs resources to be allocated | |
| _gcs_shadow_locks | number of pcm shadow locks to be allocated | |
| _gcs_testing | 0 | GCS testing parameter |
| _generalized_pruning_enabled | TRUE | controls extensions to partition pruning for general predicates |
| _ges_dd_debug | 1 | if 1 or higher enables GES deadlock detection debug diagnostics |
| _ges_diagnostics | TRUE | if TRUE enables GES diagnostics |
| _ges_health_check | 1 | if greater than 0 enables GES system health check |
| _global_hang_analysis_interval_secs | 10 | the interval at which global hang analysis is run |
| _globalindex_pnum_filter_enabled | TRUE | enables filter for global index with partition extended syntax |
| _groupby_nopushdown_cut_ratio | 3 | groupby nopushdown cut ratio |
| _groupby_orderby_combine | 5000 | groupby/orderby don’t combine threshold |
| _gs_anti_semi_join_allowed | TRUE | enable anti/semi join for the GS query |
| _hang_analysis_num_call_stacks | 3 | hang analysis num call stacks |
| _hang_detection | 60 | Hang Management detection interval |
| _hang_resolution | FALSE | Hang Management hang resolution |
| _hard_protection | FALSE | if TRUE enable H.A.R.D specific format changes |
| _hash_join_enabled | TRUE | enable/disable hash join |
| _hash_multiblock_io_count | 0 | number of blocks hash join will read/write at once |
| _heur_deadlock_resolution_secs | 0 | the heuristic wait time per node for deadlock resolution |
| _high_priority_processes | LMS*|VKTM | High Priority Process Name Mask |
| _high_server_threshold | 0 | high server thresholds |
| _hj_bit_filter_threshold | 50 | hash-join bit filtering threshold (0 always enabled) |
| _hm_analysis_oradebug_node_dump_level | 0 | the oradebug node dump level for hang manager hang analysis |
| _hm_analysis_oradebug_sys_dump_level | 0 | the oradebug system state level for hang manager hang analysis |
| _hm_analysis_output_disk | FALSE | if TRUE the hang manager outputs hang analysis results to disk |
| _hm_log_incidents | FALSE | Hang Manager incident logging |
| _hm_verification_interval | 60 | the hang manager verification interval |
| _hwm_sync_threshold | 10 | HWM synchronization threshold in percentage |
| _idl_conventional_index_maintenance | TRUE | enable conventional index maintenance for insert direct load |
| _idle_session_kill_enabled | TRUE | enables or disables resource manager session idle limit checks |
| _idxrb_rowincr | 100000000 | proportionality constant for dop vs. rows in index rebuild |
| _ignore_desc_in_index | FALSE | ignore DESC in indexes, sort those columns ascending anyhow |
| _ignore_fg_deps | ignore fine-grain dependencies during invalidation | |
| _immediate_commit_propagation | TRUE | if TRUE, propagate commit SCN immediately |
| _improved_outerjoin_card | TRUE | improved outer-join cardinality calculation |
| _improved_row_length_enabled | TRUE | enable the improvements for computing the average row length |
| _imr_active | TRUE | Activate Instance Membership Recovery feature |
| _imr_avoid_double_voting | TRUE | Avoid device voting for CSS reconfig during IMR |
| _imr_device_type | controlfile | Type of device to be used by IMR |
| _imr_disk_voting_interval | 3 | Maximum wait for IMR disk voting (seconds) |
| _imr_evicted_member_kill | TRUE | IMR issue evicted member kill after a wait |
| _imr_evicted_member_kill_wait | 20 | IMR evicted member kill wait time in seconds |
| _imr_highload_threshold | IMR system highload threshold | |
| _imr_max_reconfig_delay | 300 | Maximum Reconfiguration delay (seconds) |
| _imr_splitbrain_res_wait | 600 | Maximum wait for split-brain resolution (seconds) |
| _imr_systemload_check | TRUE | Perform the system load check during IMR |
| _imu_pools | 3 | in memory undo pools |
| _in_memory_undo | TRUE | Make in memory undo for top level transactions |
| _incremental_recovery_ckpt_min_batch | 30 | Minimum number of writes for incremental recovery ckpt every 3 sec |
| _index_join_enabled | TRUE | enable the use of index joins |
| _index_prefetch_factor | 100 | index prefetching factor |
| _init_granule_interval | 10 | number of granules to process for deferred cache |
| _init_sql_file | ?/rdbms/admin/sql.bsq | File containing SQL statements to execute upon database creation |
| _inject_startup_fault | 0 | inject fault in the startup code |
| _inline_sql_in_plsql | FALSE | inline SQL in PL/SQL |
| _insert_enable_hwm_brokered | TRUE | during parallel inserts high water marks are brokered |
| _inst_locking_period | 5 | period an instance can retain a newly acquired level1 bitmap |
| _interconnect_checksum | TRUE | if TRUE, checksum interconnect blocks |
| _intrapart_pdml_enabled | TRUE | Enable intra-partition updates/deletes |
| _intrapart_pdml_randomlocal_enabled | TRUE | Enable intra-partition updates/deletes with random local dist |
| _io_resource_manager_always_on | FALSE | io resource manager always on |
| _io_shared_pool_size | 4194304 | Size of I/O buffer pool from SGA |
| _io_slaves_disabled | FALSE | Do not use I/O slaves |
| _io_statistics | TRUE | if TRUE, ksfd I/O statistics are collected |
| _ioq_fanin_multiplier | 2 | IOQ miss count before a miss exception |
| _ior_serialize_fault | 0 | inject fault in the ior serialize code |
| _iorm_tout | 1000 | IORM scheduler timeout value in msec |
| _ioslave_batch_count | 1 | Per attempt IOs picked |
| _ioslave_issue_count | 500 | IOs issued before completion check |
| _ipc_fail_network | 0 | Simulate cluster network failer |
| _ipc_test_failover | 0 | Test transparent cluster network failover |
| _ipc_test_mult_nets | 0 | simulate multiple cluster networks |
| _job_queue_interval | 5 | Wakeup interval in seconds for job queue co-ordinator |
| _k2q_latches | 0 | number of k2q latches |
| _kcfis_fault_control | 0 | trace level setting for KCFIS module |
| _kcfis_max_appliances | 40 | Max. appliances in a KCFIS session |
| _kcfis_oss_io_size | 0 | KCFIS OSS I/O size |
| _kcfis_read_buffer_limit | 0 | KCFIS Read Buffer (per session) memory limit in bytes |
| _kcfis_trace_level | 0 | trace level setting for KCFIS module |
| _kcfis_work_set_appliances | 6 | Working Set of appliances in a KCFIS session |
| _kcl_commit | TRUE | if TRUE, call kjbcommit |
| _kcl_conservative_log_flush | FALSE | if TRUE, conservatively log flush before CR serving |
| _kcl_debug | TRUE | if TRUE, record le history |
| _kcl_index_split | TRUE | if TRUE, reject pings on blocks in middle of a split |
| _kdbl_enable_post_allocation | FALSE | allocate dbas after populating data buffers |
| _kdi_avoid_block_checking | FALSE | avoid index block checking on sensitive opcodes |
| _kdli_STOP_bsz | 0 | undocumented parameter for internal use only |
| _kdli_STOP_dba | 0 | undocumented parameter for internal use only |
| _kdli_STOP_fsz | 0 | undocumented parameter for internal use only |
| _kdli_STOP_nio | 0 | undocumented parameter for internal use only |
| _kdli_STOP_tsn | 0 | undocumented parameter for internal use only |
| _kdli_allow_corrupt | TRUE | allow corrupt filesystem_logging data blocks during read/write |
| _kdli_cache_inode | TRUE | cache inode state across calls |
| _kdli_cache_read_threshold | 0 | minimum lob size for cache->nocache read (0 disables heuristic) |
| _kdli_cache_size | 8 | maximum #entries in inode cache |
| _kdli_cache_verify | FALSE | verify cached inode via deserialization |
| _kdli_cache_write_threshold | 0 | minimum lob size for cache->nocache write (0 disables heuristic) |
| _kdli_cacheable_length | 0 | minimum lob length for inode cacheability |
| _kdli_force_cr | TRUE | force CR when reading data blocks of direct-write lobs |
| _kdli_force_cr_meta | TRUE | force CR when reading metadata blocks of direct-write lobs |
| _kdli_force_storage | none | force storage settings for all lobs |
| _kdli_full_readahead_threshold | 0 | maximum lob size for full readahead |
| _kdli_inject_assert | 0 | inject asserts into the inode |
| _kdli_inject_crash | 0 | inject crashes into the inode |
| _kdli_inline_xfm | TRUE | allow inline transformed lobs |
| _kdli_inode_preference | data | inline inode evolution preference (data, headless, lhb) |
| _kdli_itree_entries | 0 | #entries in lhb/itree blocks (for testing only) |
| _kdli_memory_protect | FALSE | trace accesses to inode memory outside kdli API functions |
| _kdli_rci_lobmap_entries | 255 | #entries in RCI lobmap before migration to lhb |
| _kdli_readahead_limit | 0 | shared/cached IO readahead limit |
| _kdli_readahead_strategy | contig | shared/cached IO readahead strategy |
| _kdli_recent_scn | FALSE | use recent (not dependent) scns for block format/allocation |
| _kdli_reshape | FALSE | reshape an inode to inline or headless on length truncation |
| _kdli_safe_callbacks | TRUE | invoke inode read/write callbacks safely |
| _kdli_sio_async | TRUE | asynchronous shared IO |
| _kdli_sio_backoff | FALSE | use exponential backoff when attempting SIOP allocations |
| _kdli_sio_bps | 0 | maximum blocks per IO slot |
| _kdli_sio_dop | 2 | degree-of-parallelism in the SIO keep pool |
| _kdli_sio_fgio | TRUE | reap asynchronous IO in the foreground |
| _kdli_sio_fileopen | nodsync | shared IO fileopen mode: datasync vs nodatasync vs async |
| _kdli_sio_flush | FALSE | enable shared IO pool operations |
| _kdli_sio_free | TRUE | free IO buffers when not in active use |
| _kdli_sio_min_read | 0 | shared IO pool read threshold |
| _kdli_sio_min_write | 0 | shared IO pool write threshold |
| _kdli_sio_nbufs | 8 | maximum #IO buffers to allocate per session |
| _kdli_sio_niods | 8 | maximum #IO descriptors to allocate per session |
| _kdli_sio_on | TRUE | enable shared IO pool operations |
| _kdli_sio_pga | FALSE | use PGA allocations for direct IO |
| _kdli_sio_pga_top | FALSE | PGA allocations come from toplevel PGA heap |
| _kdli_sio_strategy | auto | shared IO strategy: block vs. extent |
| _kdli_small_cache_limit | 32 | size limit of small inode cache |
| _kdli_sort_dbas | FALSE | sort dbas during chunkification |
| _kdli_space_cache_limit | 2048 | maximum size of the space cache in #blocks |
| _kdli_squeeze | TRUE | compact lobmap extents with contiguous dbas |
| _kdli_timer_dmp | FALSE | dump inode timers on session termination |
| _kdli_timer_trc | FALSE | trace inode timers to uts/tracefile |
| _kdli_trace | 0 | inode trace level |
| _kdlu_max_bucket_size | 4194304 | UTS kdlu bucket size |
| _kdlu_max_bucket_size_mts | 131072 | UTS kdlu bucket size for mts |
| _kdlu_trace_layer | 0 | UTS kdlu per-layer trace level |
| _kdlu_trace_session | 0 | UTS session dump |
| _kdlu_trace_system | 0 | UTS system dump |
| _kdlw_enable_ksi_locking | FALSE | enable ksi locking for lobs |
| _kdlw_enable_write_gathering | TRUE | enable lob write gathering for sql txns |
| _kdlwp_flush_threshold | 4194304 | WGC flush threshold in bytes |
| _kdlxp_cmp_subunit_size | 262144 | size of compression sub-unit in bytes |
| _kdlxp_dedup_flush_threshold | 8388608 | deduplication flush threshold in bytes |
| _kdlxp_dedup_hash_algo | SHA1 | secure hash algorithm for deduplication – only on SecureFiles |
| _kdlxp_dedup_prefix_threshold | 1048576 | deduplication prefix hash threshold in bytes |
| _kdlxp_lobcompress | FALSE | enable lob compression – only on SecureFiles |
| _kdlxp_lobdeduplicate | FALSE | enable lob deduplication – only on SecureFiles |
| _kdlxp_lobdedupvalidate | TRUE | enable deduplicate validate – only on SecureFiles |
| _kdlxp_lobencrypt | FALSE | enable lob encryption – only on SecureFiles |
| _kdlxp_min_xfm_size | 32768 | minimum transformation size in bytes |
| _kdlxp_mincmp | 20 | minimum comp ratio in pct – only on SecureFiles |
| _kdlxp_spare1 | 0 | deduplication spare 1 |
| _kdlxp_xfmcache | TRUE | enable xfm cache – only on SecureFiles |
| _kdt_buffering | TRUE | control kdt buffering for conventional inserts |
| _kebm_nstrikes | 3 | kebm # strikes to auto suspend an action |
| _kebm_suspension_time | 82800 | kebm auto suspension time in seconds |
| _keep_remote_column_size | FALSE | remote column size does not get modified |
| _kernel_message_network_driver | FALSE | kernel message network driver |
| _kffmap_hash_size | 1024 | size of kffmap_hash table |
| _kffmop_hash_size | 2048 | size of kffmop_hash table |
| _kfm_disable_set_fence | FALSE | disable set fence calls and revert to default (process fence) |
| _kghdsidx_count | 1 | max kghdsidx count |
| _kgl_bucket_count | 9 | index to the bucket count array |
| _kgl_debug | Library cache debugging | |
| _kgl_features_enabled | 2 | Library cache features enabled bits |
| _kgl_fixed_extents | TRUE | fixed extent size for library cache memory allocations |
| _kgl_hash_collision | FALSE | whether KGL hash collision is possible |
| _kgl_heap_size | 1024 | extent size for library cache heap 0 |
| _kgl_kqr_cap_so_stacks | FALSE | capture stacks for library and row cache state objects |
| _kgl_large_heap_warning_threshold | 52428800 | maximum heap size before KGL writes warnings to the alert log |
| _kgl_latch_count | 0 | number of library cache latches |
| _kgl_message_locks | 64 | RAC message lock count |
| _kgl_min_cached_so_count | 1 | Minimum cached SO count. If > 1 can help find SO corruptions |
| _kgl_multi_instance_invalidation | TRUE | whether KGL to support multi-instance invalidations |
| _kgl_multi_instance_lock | TRUE | whether KGL to support multi-instance locks |
| _kgl_multi_instance_pin | TRUE | whether KGL to support multi-instance pins |
| _kgl_so_stack_depth | 16 | The depth of the stack capture for SO get or free |
| _kgl_time_to_wait_for_locks | 15 | time to wait for locks and pins before timing out |
| _kglsim_maxmem_percent | 5 | max percentage of shared pool size to be used for KGL advice |
| _kgsb_threshold_size | 16777216 | threshold size for base allocator |
| _kgx_latches | 1024 | # of mutex latches if CAS is not supported. |
| _kgx_spin_count | 255 | third spare parameter – integer |
| _kill_controlfile_enqueue_blocker | TRUE | enable killing controlfile enqueue blocker on timeout |
| _kill_diagnostics_timeout | 60 | timeout delay in seconds before killing enqueue blocker |
| _kill_enqueue_blocker | 2 | if greater than 0 enables killing enqueue blocker |
| _kill_java_threads_on_eoc | FALSE | Kill Java threads and do sessionspace migration at end of call |
| _kill_session_dump | TRUE | Process dump on kill session immediate |
| _kkdlgon_max_iter | 20000 | kkdlgon maximum number of iterations |
| _kkfi_trace | FALSE | trace expression substitution |
| _kks_free_cursor_stat_pct | 10 | percentage of cursor stats buckets to scan on each load, in 1/10th of a percent |
| _kks_use_mutex_pin | TRUE | Turning on this will make KKS use mutex for cursor pins. |
| _kokli_cache_size | 32 | Size limit of Materialized View and Object Table Lookup Cache |
| _kolfuseslf | FALSE | allow kolf to use slffopen |
| _kql_subheap_trace | 0 | tracing level for library cache subheap level pins |
| _ksb_disable_diagpid | FALSE | disable the call to ksb_diagpid |
| _ksb_restart_clean_time | 30000 | process uptime for restarts |
| _ksb_restart_policy_times | 0, 60, 120, 240 | process restart policy times in seconds |
| _ksd_test_param | 999 | KSD test parmeter |
| _ksdxdocmd_default_timeout_ms | 30000 | default timeout for internal oradebug commands |
| _ksdxdocmd_enabled | TRUE | if TRUE ksdxdocmd* invocations are enabled |
| _ksdxw_cini_flg | 0 | ksdxw context initialization flag |
| _ksdxw_nbufs | 1000 | ksdxw number of buffers in buffered mode |
| _ksdxw_num_pgw | 10 | number of watchpoints on a per-process basis |
| _ksdxw_num_sgw | 10 | number of watchpoints to be shared by all processes |
| _ksdxw_stack_depth | 4 | number of PCs to collect in the stack when watchpoint is hit |
| _kse_die_timeout | 60000 | amount of time a dying process is spared by PMON (in centi-secs) |
| _kse_pc_table_size | 256 | kse pc table cache size |
| _kse_signature_entries | 0 | number of entries in the kse stack signature cache |
| _kse_signature_limit | 7 | number of stack frames to cache per kse signature |
| _kse_snap_ring_size | 0 | ring buffer to debug internal error 17090 |
| _ksfd_verify_write | FALSE | verify asynchronous writes issued through ksfd |
| _ksi_trace | KSI trace string of lock type(s) | |
| _ksi_trace_bucket | PRIVATE | memory tracing: use ksi-private or rdbms-shared bucket |
| _ksi_trace_bucket_size | 8192 | size of the KSI trace bucket |
| _ksmb_debug | 0 | ksmb debug flags |
| _ksmd_protect_mode | off | KSMD protect mode for catching stale access |
| _ksmg_granule_locking_status | 1 | granule locking status |
| _ksmg_granule_size | 4194304 | granule size in bytes |
| _ksmg_lock_check_interval | timeout action interval in minutes | |
| _ksmg_lock_reacquire_count | 5 | repeat count for acquisition of locks |
| _kspol_tac_timeout | 5 | timeouts for TAC registerd by kspol |
| _ksr_unit_test_processes | 0 | number of ksr unit test processes |
| _kss_quiet | FALSE | if TRUE access violations during kss dumps are not recorded |
| _ksu_diag_kill_time | 5 | number of seconds ksuitm waits before killing diag |
| _ksuitm_addon_trccmd | command to execute when dead processes don’t go away | |
| _ksuitm_dont_kill_dumper | FALSE | delay inst. termination to allow processes to dump |
| _ksv_max_spawn_fail_limit | 5 | bg slave spawn failure limit |
| _ksv_pool_hang_kill_to | 0 | bg slave pool terminate timeout |
| _ksv_pool_wait_timeout | 600 | bg slave pool wait limit |
| _ksv_spawn_control_all | FALSE | control all spawning of background slaves |
| _ksvppktmode | 0 | ksv internal pkt test |
| _ksxp_diagmode | OFF | set to OFF to disable automatic slowsend diagnostics |
| _ksxp_disable_dynamic_loading | FALSE | disable dynamic loadin of lib skgxp |
| _ksxp_disable_ipc_stats | FALSE | disable ipc statistics |
| _ksxp_init_stats_bkts | 0 | initial number arrays for ipc statistics |
| _ksxp_max_stats_bkts | 0 | max. arrays for ipc statistics |
| _ksxp_ping_enable | TRUE | disable dynamic loadin of lib skgxp |
| _ksxp_ping_polling_time | 0 | max. arrays for ipc statistics |
| _ksxp_reaping | 20 | tune ksxp layer reaping limit |
| _ksxp_reporting_process | LMD0 | reporting process for KSXP |
| _ksxp_send_timeout | 300 | set timeout for sends queued with the inter-instance IPC |
| _ksxp_skgxp_compat_library_path | over-ride default location of lib skgxp compat | |
| _ksxp_skgxp_library_path | over-ride default location of lib skgxp | |
| _ksxp_stats_mem_lmt | 0 | limit ipc statistics memory. this parameter is a percentage value |
| _ksxp_testing | 0 | KSXP test parameter |
| _ksxp_unit_test_byte_transformation | FALSE | enable byte transformation unit test |
| _ktc_debug | 0 | for ktc debug |
| _ktc_latches | 0 | number of ktc latches |
| _ktslj_segext_warning | 10 | segment pre-extension warning threshold in percentage |
| _ktspsrch_maxsc | 32 | maximum segments supported by space search cache |
| _kttext_warning | 5 | tablespace pre-extension warning threshold in percentage |
| _ktu_latches | 0 | number of KTU latches |
| _ku_trace | none | datapump trace parameter |
| _large_pool_min_alloc | 16000 | minimum allocation size in bytes for the large allocation pool |
| _last_allocation_period | 5 | period over which an instance can retain an active level1 bitmap |
| _latch_class_0 | latch class 0 | |
| _latch_class_1 | latch class 1 | |
| _latch_class_2 | latch class 2 | |
| _latch_class_3 | latch class 3 | |
| _latch_class_4 | latch class 4 | |
| _latch_class_5 | latch class 5 | |
| _latch_class_6 | latch class 6 | |
| _latch_class_7 | latch class 7 | |
| _latch_classes | latch classes override | |
| _latch_miss_stat_sid | 0 | Sid of process for which to collect latch stats |
| _latch_recovery_alignment | 65534 | align latch recovery structures |
| _ldr_io_size | 262144 | size of write IOs used during a load operation |
| _left_nested_loops_random | TRUE | enable random distribution method for left of nestedloops |
| _lgwr_async_broadcasts | TRUE | LGWR Asynchronous Broadcasts enabling boolean flag |
| _lgwr_delay_write | FALSE | LGWR write delay for debugging |
| _lgwr_io_slaves | 0 | LGWR I/O slaves |
| _lgwr_max_ns_wt | 1 | Maximum wait time for lgwr to allow NetServer to progress |
| _lgwr_ns_nl_max | 1000 | Variable to simulate network latency or buffer threshold |
| _lgwr_ns_nl_min | 500 | Variable to simulate network latency or buffer threshold |
| _lgwr_ns_sim_err | 0 | Variable to simulate errors lgwrns |
| _lgwr_ta_sim_err | 0 | Variable to simulate errors lgwr true async |
| _library_cache_advice | TRUE | whether KGL advice should be turned on |
| _lightweight_hdrs | TRUE | Lightweight headers for redo |
| _like_with_bind_as_equality | FALSE | treat LIKE predicate with bind as an equality predicate |
| _lm_activate_lms_threshold | 100 | threshold value to activate an additional lms |
| _lm_asm_enq_hashing | TRUE | if TRUE makes ASM use enqueue master hashing for fusion locks |
| _lm_better_ddvictim | TRUE | GES better deadlock victim |
| _lm_cache_lvl0_cleanup | 0 | how often to cleanup level 0 cache res (in sec) |
| _lm_cache_res_cleanup | 25 | percentage of cached resources should be cleanup |
| _lm_cache_res_type | TMHWDI | cache resource: string of lock types(s) |
| _lm_checksum_batch_msg | 0 | GES checksum batch messages |
| _lm_contiguous_res_count | 128 | number of contiguous blocks that will hash to the same HV bucket |
| _lm_dd_interval | 10 | dd time interval in seconds |
| _lm_dd_max_search_time | 180 | max dd search time per token |
| _lm_dd_scan_interval | 5 | dd scan interval in seconds |
| _lm_dd_search_cnt | 3 | number of dd search per token get |
| _lm_drm_max_requests | 100 | dynamic remastering maximum affinity requests processed together |
| _lm_drm_window | 0 | dynamic remastering bucket window size |
| _lm_drm_xlatch | 0 | dynamic remastering forced exclusive latches |
| _lm_dynamic_lms | FALSE | dynamic lms invocation |
| _lm_dynamic_load | TRUE | dynamic load adjustment |
| _lm_enq_lock_freelist | Number of ges enqueue element freelist | |
| _lm_enq_rcfg | TRUE | if TRUE enables enqueue reconfiguration |
| _lm_enqueue_freelist | 3 | Number of enqueue freelist |
| _lm_file_affinity | mapping between file id and master instance number | |
| _lm_global_posts | TRUE | if TRUE deliver global posts to remote nodes |
| _lm_idle_connection_check | TRUE | GES idle connection check |
| _lm_idle_connection_check_interval | 10 | GES idle connection check interval time |
| _lm_idle_connection_kill | FALSE | GES idle connection kill |
| _lm_lmd_waittime | 8 | default wait time for lmd in centiseconds |
| _lm_lmon_nowait_latch | TRUE | if TRUE makes lmon get nowait latches with timeout loop |
| _lm_lms | 0 | number of background gcs server processes to start |
| _lm_lms_waittime | 8 | default wait time for lms in centiseconds |
| _lm_locks | 12000 | number of enqueues configured for cluster database |
| _lm_master_weight | 1 | master resource weight for this instance |
| _lm_max_lms | 0 | max. number of background global cache server processes |
| _lm_msg_batch_size | 0 | GES batch message size |
| _lm_msg_cleanup_interval | 3000 | GES message buffer cleanup interval time |
| _lm_node_join_opt | FALSE | cluster database node join optimization in reconfig |
| _lm_non_fault_tolerant | FALSE | disable cluster database fault-tolerance mode |
| _lm_num_pt_buckets | 8192 | number of buckets in the object affinity hash table |
| _lm_num_pt_latches | 128 | number of latches in the object affinity hash table |
| _lm_postevent_buffer_size | 256 | postevent buffer size |
| _lm_proc_freeze_timeout | 300 | reconfiguration: process freeze timeout |
| _lm_process_batching | TRUE | GES implicit process batching for IPC messages |
| _lm_procs | 320 | number of client processes configured for cluster database |
| _lm_psrcfg | FALSE | enable pseudo reconfiguration |
| _lm_rcfg_timeout | 1260 | Reconfiguration timeout |
| _lm_rcvr_hang_allow_time | 200 | receiver hang allow time in seconds |
| _lm_rcvr_hang_check_frequency | 60 | receiver hang check frequency in seconds |
| _lm_rcvr_hang_kill | FALSE | to kill receiver hang |
| _lm_res_hash_bucket | 0 | number of resource hash buckets |
| _lm_res_part | 128 | number of resource partition configured for gcs |
| _lm_ress | 6000 | number of resources configured for cluster database |
| _lm_send_mode | auto | GES send mode |
| _lm_send_queue_batching | TRUE | GES send queue message batching |
| _lm_send_queue_length | 5000 | GES send queue maximum length |
| _lm_sendproxy_reserve | 25 | GES percentage of send proxy reserve of send tickets |
| _lm_share_lock_opt | FALSE | if TRUE enables share lock optimization |
| _lm_sq_batch_factor | 2 | GES send queue minimum batching factor |
| _lm_sq_batch_type | auto | GES send queue batching mechanism |
| _lm_sq_batch_waittick | 3 | GES send queue batching waittime in tick |
| _lm_sync_timeout | 420 | Synchronization timeout for DLM reconfiguration steps |
| _lm_ticket_active_sendback | Flow control ticket active sendback threshold | |
| _lm_tickets | 1000 | GES messaging tickets |
| _lm_tx_delta | 16 | TX lock localization delta |
| _lm_validate_resource_type | FALSE | if TRUE enables resource name validation |
| _lm_xids | 352 | number of transaction IDs configured for cluster database |
| _lmn_compression | FALSE | suppl logging for compression enabled |
| _load_without_compile | NONE | Load PL/SQL or Database objects without compilation |
| _local_communication_costing_enabled | TRUE | enable local communication costing when TRUE |
| _local_communication_ratio | 50 | set the ratio between global and local communication (0..100) |
| _local_hang_analysis_interval_secs | 3 | the interval at which local hang analysis is run |
| _lock_sga_areas | 0 | Lock specified areas of the SGA in physical memory |
| _log_archive_avoid_memcpy | TRUE | log archive avoid memcpy |
| _log_archive_buffers | 10 | Number of buffers to allocate for archiving |
| _log_archive_callout | archival callout | |
| _log_archive_compress_enable | FALSE | Bypass database rules for enabling archivelog compression |
| _log_archive_network_redo_size | 10 | Log archive network redo buffer size used by ARCH |
| _log_archive_prot_auto_demote | FALSE | log archive protection auto demotion |
| _log_archive_security_enabled | TRUE | log archive security enabled |
| _log_archive_strong_auth | TRUE | log archive security strong auth |
| _log_blocks_during_backup | TRUE | log block images when changed during backup |
| _log_buffers_corrupt | FALSE | corrupt redo buffers before write |
| _log_buffers_debug | FALSE | debug redo buffers (slows things down) |
| _log_checkpoint_recovery_check | 0 | # redo blocks to verify after checkpoint |
| _log_committime_block_cleanout | FALSE | Log commit-time block cleanout |
| _log_deletion_policy | mandatory | archivelog deletion policy for mandatory/all destination |
| _log_event_queues | 0 | number of the log writer event queues |
| _log_io_size | 0 | automatically initiate log write if this many redo blocks in buffer |
| _log_parallelism_dynamic | TRUE | Enable dynamic strands |
| _log_parallelism_max | 1 | Maximum number of log buffer strands |
| _log_private_mul | 5 | Private strand multiplier for log space preallocation |
| _log_private_parallelism | FALSE | Number of private log buffer strands for zero-copy redo |
| _log_private_parallelism_mul | 10 | Active sessions multiplier to deduce number of private strands |
| _log_read_buffers | 4 | Number of log read buffers for media recovery |
| _log_simultaneous_copies | 2 | number of simultaneous copies into redo buffer(# of copy latches) |
| _log_space_errors | TRUE | should we report space errors to alert log |
| _log_switch_timeout | 0 | Maximum number of seconds redos in the current log could span |
| _logout_storm_rate | 0 | number of processes that can logout in a second |
| _logout_storm_retrycnt | 600 | maximum retry count for logouts |
| _logout_storm_timeout | 5 | timeout in centi-seconds for time to wait between retries |
| _longops_enabled | TRUE | longops stats enabled |
| _low_server_threshold | 0 | low server thresholds |
| _ltc_trace | 0 | tracing level for load table conventional |
| _master_direct_sends | 31 | direct sends for messages from master (DFS) |
| _mav_refresh_consistent_read | TRUE | refresh materialized views using consistent read snapshot |
| _mav_refresh_double_count_prevented | FALSE | materialized view MAV refreshes avoid double counting |
| _mav_refresh_opt | 0 | optimizations during refresh of materialized views |
| _mav_refresh_unionall_tables | 3 | # tables for union all expansion during materialized view refresh |
| _max_arch_lns_wait | 120 | Maximum wait by ARCH to allow NetServer to complete archival |
| _max_exponential_sleep | 0 | max sleep during exponential backoff |
| _max_io_size | 1048576 | Maximum I/O size in bytes for sequential file accesses |
| _max_large_io | 0 | IORM:max number of large I/O’s to issue |
| _max_lns_shutdown_archival_time | 30 | Maximum time spent by LNS to archive last log during shutdown |
| _max_protocol_support | 10000 | Max occurrence protocols supported in a process |
| _max_shrink_obj_stats | 0 | number of segments for which shrink stats will be maintained |
| _max_sleep_holding_latch | 4 | max time to sleep while holding a latch |
| _max_small_io | 0 | IORM:max number of small I/O’s to issue |
| _max_spacebg_slaves | 10 | maximum space management background slaves |
| _max_spacebg_tasks | 1000 | maximum space management background tasks |
| _max_temp_overhead | 0 | max tempspc overhead |
| _media_recovery_read_batch | 128 | media recovery block read batch |
| _mem_annotation_pr_lev | 0 | private memory annotation collection level |
| _mem_annotation_scale | 1 | memory annotation pre-allocation scaling |
| _mem_annotation_sh_lev | 0 | shared memory annotation collection level |
| _mem_annotation_store | FALSE | memory annotation in-memory store |
| _mem_std_extent_size | 4096 | standard extent size for fixed-size-extent heaps |
| _memory_broker_log_stat_entries | 5 | memory broker num stat entries |
| _memory_broker_marginal_utility_bc | 12 | Marginal Utility threshold pct for bc |
| _memory_broker_marginal_utility_sp | 7 | Marginal Utility threshold pct for sp |
| _memory_broker_shrink_heaps | 15 | memory broker allow policy to shrink shared pool |
| _memory_broker_shrink_java_heaps | 900 | memory broker allow policy to shrink java pool |
| _memory_broker_shrink_streams_pool | 900 | memory broker allow policy to shrink streams pool |
| _memory_broker_shrink_timeout | 60000000 | memory broker policy to timeout shrink shared/java pool |
| _memory_broker_stat_interval | 30 | memory broker statistics gathering interval for auto sga |
| _memory_management_tracing | 0 | trace memory management activity |
| _memory_nocancel_defsgareq | FALSE | do not cancel deferred sga reqs with auto-memory |
| _memory_sanity_check | 0 | partial granule sanity check |
| _messages | 300 | message queue resources – dependent on # processes & # buffers |
| _midtier_affinity_clusterwait_threshold | 100 | cluster wait threshold to enter affinity |
| _midtier_affinity_goodness_threshold | 2000 | goodness gradient threshold to dissolve affinity |
| _midtier_affinity_timeout | 30000 | default timeout for midtier affinity processing |
| _minfree_plus | 0 | max percentage of block space + minfree before we mark block full |
| _minimal_stats_aggregation | TRUE | prohibit stats aggregation at compile/partition maintenance time |
| _minimum_blocks_to_shrink | 0 | minimum number freeable blocks for shrink to be present |
| _minimum_db_flashback_retention | 60 | Minimum flashback retention |
| _minimum_extents_to_shrink | 1 | minimum number freeable extents for shrink to be present |
| _minimum_giga_scn | 0 | Minimum SCN to start with in 2^30 units |
| _mirror_redo_buffers | FALSE | Save buffers for debugging redo corruptions |
| _mmv_query_rewrite_enabled | TRUE | allow rewrites with multiple MVs and/or base tables |
| _multi_instance_pmr | TRUE | force multi instance or single instance parallel recovery |
| _multi_join_key_table_lookup | TRUE | TRUE iff multi-join-key table lookup prefetch is enabled |
| _multiple_instance_recovery | FALSE | use multiple instances for media recovery |
| _mv_refresh_ana | 0 | what percent to analyze after complete/PCT refresh |
| _mv_refresh_costing | rule | refresh decision based on cost or on rules |
| _mv_refresh_delta_fraction | 10 | delta mv as fractional percentage of size of mv |
| _mv_refresh_eut | TRUE | refresh materialized views using EUT(partition)-based algorithm |
| _mv_refresh_force_parallel_query | 0 | force materialized view refreshes to use parallel query |
| _mv_refresh_new_setup_disabled | FALSE | materialized view MV refresh new setup disabling |
| _mv_refresh_rebuild_percentage | 10 | minimum percentage change required in MV to force an indexrebuild |
| _mv_refresh_selections | TRUE | create materialized views with selections and fast refresh |
| _mv_refresh_use_stats | FALSE | pass cardinality hints to refresh queries |
| _mv_refsched_timeincr | 300000 | proportionality constant for dop vs. time in MV refresh |
| _mv_rolling_inv | FALSE | create/alter mv uses rolling cursor invalidation instead of immediate |
| _mwin_schedule | TRUE | Enable/disable Maintenance Window Schedules |
| _nchar_imp_cnv | TRUE | NLS allow Implicit Conversion between CHAR and NCHAR |
| _nchar_imp_conv | TRUE | should implicit conversion bewteen clob and nclob be allowed |
| _ncmb_readahead_enabled | 0 | enable multi-block readahead for an index scan |
| _ncmb_readahead_tracing | 0 | turn on multi-block readahead tracing |
| _ncomp_shared_objects_dir | native compilation shared objects dir | |
| _nested_loop_fudge | 100 | nested loop fudge |
| _nested_mav_fast_oncommit_enabled | TRUE | nested MAV refresh fast on commit allowed |
| _new_initial_join_orders | TRUE | enable initial join orders based on new ordering heuristics |
| _new_sort_cost_estimate | TRUE | enables the use of new cost estimate for sort |
| _newsort_enabled | TRUE | controls whether new sorts can be used as system sort |
| _newsort_ordered_pct | 63 | controls when new sort avoids sorting ordered input |
| _newsort_type | 0 | specifies options for the new sort algorithm |
| _nlj_batching_enabled | 1 | enable batching of the RHS IO in NLJ |
| _nlj_batching_misses_enabled | 1 | enable exceptions for buffer cache misses |
| _no_objects | FALSE | no object features are used |
| _no_or_expansion | FALSE | OR expansion during optimization disabled |
| _no_recovery_through_resetlogs | FALSE | no recovery through this resetlogs operation |
| _notify_crs | FALSE | notify cluster ready services of startup and shutdown |
| _ns_max_flush_wt | 1 | Flush wait time for NetServer to flush oustanding writes |
| _ns_max_send_delay | 15 | Data Loss Time Bound for NetServer |
| _num_longop_child_latches | 1 | number of child latches for long op array |
| _number_cached_attributes | 10 | maximum number of cached attributes per instance |
| _object_reuse_bast | 2 | if 1 or higher, handle object reuse |
| _object_statistics | TRUE | enable the object level statistics collection |
| _object_stats_max_entries | 3072 | Maximum number of entries to be tracked per stat |
| _offline_rollback_segments | offline undo segment list | |
| _ogms_home | GMS home directory | |
| _olap_aggregate_buffer_size | 1048576 | OLAP Aggregate max buffer size |
| _olap_aggregate_flags | 0 | OLAP Aggregate debug flags |
| _olap_aggregate_function_cache_enabled | TRUE | OLAP Aggregate function cache enabler |
| _olap_aggregate_function_merge_threshold | 529 | OLAP Aggregate function merge threshold |
| _olap_aggregate_max_thread_tuples | 5000 | OLAP Aggregate max thread tuples creation |
| _olap_aggregate_min_buffer_size | 1024 | OLAP Aggregate min buffer size |
| _olap_aggregate_min_thread_status | 64 | OLAP Aggregate minimum cardinality of dimensions for thread |
| _olap_aggregate_multipath_hier | FALSE | OLAP Aggregate Multi-path Hierarhies enabled |
| _olap_aggregate_statlen_thresh | 1024 | OLAP Aggregate status array usage threshold |
| _olap_aggregate_store_probability | 100 | OLAP Aggregate function storeback probability |
| _olap_aggregate_work_per_thread | 1024 | OLAP Aggregate max work parents |
| _olap_aggregate_worklist_max | 5000 | OLAP Aggregate max worklists generated at once |
| _olap_allocate_errorlog_format | %8p %8y %8z %e (%n) | OLAP Allocate Errorlog Format |
| _olap_allocate_errorlog_header | Dim Source Basis %-8d %-8s %-8b Description ——– ——– ——– ———– | OLAP Allocate Errorlog Header format |
| _olap_analyze_max | 10000 | OLAP DML ANALYZE command max cells to analyze |
| _olap_continuous_trace_file | FALSE | Specify TRUE to enable continuous OLAP tracing – otherwise only exceptional events will be logged |
| _olap_dbgoutfile_echo_to_eventlog | FALSE | OLAP DbgOutfile copy output to event log (tracefile) |
| _olap_dimension_corehash_class | 1 | OLAP Dimension In-Core Hash Table Class |
| _olap_dimension_corehash_large | 50000 | OLAP Dimension In-Core Hash Table Large Threshold |
| _olap_dimension_corehash_pressure | 90 | OLAP Dimension In-Core Hash Table Pressure Threshold |
| _olap_dimension_corehash_size | 30 | OLAP Dimension In-Core Hash Table Maximum Memory Use |
| _olap_dimension_corehash_small | 1000 | OLAP Dimension In-Core Hash Table Small Threshold |
| _olap_eif_export_lob_size | 2147483647 | OLAP EIF Export BLOB size |
| _olap_lmgen_dim_size | 100 | Limitmap generator dimension column size |
| _olap_lmgen_meas_size | 1000 | Limitmap generator measure column size |
| _olap_object_hash_class | 2 | OLAP Object Hash Table Class |
| _olap_page_pool_expand_rate | 20 | OLAP Page Pool Expand Rate |
| _olap_page_pool_hi | 50 | OLAP Page Pool High Watermark |
| _olap_page_pool_hit_target | 100 | OLAP Page Pool Hit Target |
| _olap_page_pool_low | 262144 | OLAP Page Pool Low Watermark |
| _olap_page_pool_pressure | 90 | OLAP Page Pool Pressure Threshold |
| _olap_page_pool_shrink_rate | 50 | OLAP Page Pool Shrink Rate |
| _olap_parallel_update_small_group | 400 | OLAP parallel update pagespace by group |
| _olap_parallel_update_small_threshold | 1000 | OLAP parallel update threshold for number of small pagespaces |
| _olap_parallel_update_threshold | 1000 | OLAP parallel update threshold in pages |
| _olap_poutlog_echo_to_eventlog | FALSE | OLAP POutLog copy output to event log (tracefile) |
| _olap_sesscache_enabled | TRUE | OLAP Session Cache knob |
| _olap_sort_buffer_size | 262144 | OLAP Sort Buffer Size |
| _olap_statbool_corebits | 20000000 | OLAP Status Boolean max incore bits |
| _olap_statbool_threshold | 8100 | OLAP Status Boolean CBM threshold |
| _olap_table_function_statistics | FALSE | Specify TRUE to output OLAP table function timed statistics trace |
| _olap_wrap_errors | FALSE | Wrap error messages to OLAP outfile |
| _olapi_history_retention | FALSE | enable olapi history retention |
| _olapi_iface_object_history | 1000 | enable olapi interface object history collection |
| _olapi_iface_object_history_retention | FALSE | enable olapi interface object history retention |
| _olapi_iface_operation_history_retention | FALSE | enable olapi interface operation history retention |
| _olapi_interface_operation_history | 1000 | enable olapi interface operation history collection |
| _olapi_memory_operation_history | 1000 | enable olapi memory alloc/free history collection |
| _olapi_memory_operation_history_pause_at_seqno | 0 | enable olapi memory alloc/free history collection pausing |
| _olapi_memory_operation_history_retention | FALSE | enable olapi memory operation history retention |
| _olapi_session_history | 300 | enable olapi session history collection |
| _olapi_session_history_retention | FALSE | enable olapi session history retention |
| _old_connect_by_enabled | FALSE | enable/disable old connect by |
| _ols_cleanup_task | TRUE | Clean up unnecessary entries in OLS sessinfo table |
| _oltp_compression | TRUE | oltp compression enabled |
| _oltp_compression_gain | 10 | oltp compression gain |
| _omf | enabled | enable/disable OMF |
| _oneside_colstat_for_equijoins | TRUE | sanity check on default selectivity for like/range predicate |
| _online_patch_disable_stack_check | FALSE | disable check for function on stack for online patches |
| _optim_adjust_for_part_skews | TRUE | adjust stats for skews across partitions |
| _optim_dict_stats_at_db_cr_upg | TRUE | enable/disable dictionary stats gathering at db create/upgrade |
| _optim_enhance_nnull_detection | TRUE | TRUE to enable index [fast] full scan more often |
| _optim_new_default_join_sel | TRUE | improves the way default equijoin selectivity are computed |
| _optim_peek_user_binds | TRUE | enable peeking of user binds |
| _optimizer_adaptive_cursor_sharing | TRUE | optimizer adaptive cursor sharing |
| _optimizer_adjust_for_nulls | TRUE | adjust selectivity for null values |
| _optimizer_autostats_job | TRUE | enable/disable auto stats collection job |
| _optimizer_aw_join_push_enabled | TRUE | Enables AW Join Push optimization |
| _optimizer_aw_stats_enabled | TRUE | Enables statistcs on AW olap_table table function |
| _optimizer_better_inlist_costing | ALL | enable improved costing of index access using in-list(s) |
| _optimizer_block_size | 8192 | standard block size used by optimizer |
| _optimizer_cache_stats | FALSE | cost with cache statistics |
| _optimizer_cartesian_enabled | TRUE | optimizer cartesian join enabled |
| _optimizer_cbqt_factor | 50 | cost factor for cost-based query transformation |
| _optimizer_cbqt_no_size_restriction | TRUE | disable cost based transformation query size restriction |
| _optimizer_ceil_cost | TRUE | CEIL cost in CBO |
| _optimizer_choose_permutation | 0 | force the optimizer to use the specified permutation |
| _optimizer_complex_pred_selectivity | TRUE | enable selectivity estimation for builtin functions |
| _optimizer_compute_index_stats | TRUE | force index stats collection on index creation/rebuild |
| _optimizer_connect_by_combine_sw | TRUE | combine no filtering connect by and start with |
| _optimizer_connect_by_cost_based | TRUE | use cost-based transformation for connect by |
| _optimizer_correct_sq_selectivity | TRUE | force correct computation of subquery selectivity |
| _optimizer_cost_based_transformation | LINEAR | enables cost-based query transformation |
| _optimizer_cost_filter_pred | FALSE | enables costing of filter predicates in IO cost model |
| _optimizer_cost_hjsmj_multimatch | TRUE | add cost of generating result set when #rows per key > 1 |
| _optimizer_cost_model | CHOOSE | optimizer cost model |
| _optimizer_degree | 0 | force the optimizer to use the same degree of parallelism |
| _optimizer_dim_subq_join_sel | TRUE | use join selectivity in choosing star transformation dimensions |
| _optimizer_disable_strans_sanity_checks | 0 | disable star transformation sanity checks |
| _optimizer_distinct_elimination | TRUE | Eliminates redundant SELECT DISTNCT’s |
| _optimizer_dyn_smp_blks | 32 | number of blocks for optimizer dynamic sampling |
| _optimizer_enable_density_improvements | TRUE | use improved density computation for selectivity estimation |
| _optimizer_enable_extended_stats | TRUE | use extended statistics for selectivity estimation |
| _optimizer_enhanced_filter_push | TRUE | push filters before trying cost-based query transformation |
| _optimizer_extend_jppd_view_types | TRUE | join pred pushdown on group-by, distinct, semi-/anti-joined view |
| _optimizer_extended_cursor_sharing | UDO | optimizer extended cursor sharing |
| _optimizer_extended_cursor_sharing_rel | SIMPLE | optimizer extended cursor sharing for relational operators |
| _optimizer_extended_stats_usage_control | 240 | controls the optimizer usage of extended stats |
| _optimizer_filter_pred_pullup | TRUE | use cost-based flter predicate pull up transformation |
| _optimizer_fkr_index_cost_bias | 10 | Optimizer index bias over FTS/IFFS under first K rows mode |
| _optimizer_free_transformation_heap | TRUE | free transformation subheap after each transformation |
| _optimizer_group_by_placement | TRUE | consider group-by placement optimization |
| _optimizer_ignore_hints | FALSE | enables the embedded hints to be ignored |
| _optimizer_improve_selectivity | TRUE | improve table and partial overlap join selectivity computation |
| _optimizer_invalidation_period | 18000 | time window for invalidation of cursors of analyzed objects |
| _optimizer_join_elimination_enabled | TRUE | optimizer join elimination enabled |
| _optimizer_join_order_control | 3 | controls the optimizer join order search algorithm |
| _optimizer_join_sel_sanity_check | TRUE | enable/disable sanity check for multi-column join selectivity |
| _optimizer_max_permutations | 2000 | optimizer maximum join permutations per query block |
| _optimizer_min_cache_blocks | 10 | set minimum cached blocks |
| _optimizer_mjc_enabled | TRUE | enable merge join cartesian |
| _optimizer_mode_force | TRUE | force setting of optimizer mode for user recursive SQL also |
| _optimizer_multi_level_push_pred | TRUE | consider join-predicate pushdown that requires multi-level pushdown to base table |
| _optimizer_multiple_cenv | generate and run plans using several compilation environments | |
| _optimizer_native_full_outer_join | FORCE | execute full outer join using native implementaion |
| _optimizer_nested_rollup_for_gset | 100 | number of groups above which we use nested rollup exec for gset |
| _optimizer_new_join_card_computation | TRUE | compute join cardinality using non-rounded input values |
| _optimizer_null_aware_antijoin | TRUE | null-aware antijoin parameter |
| _optimizer_or_expansion | DEPTH | control or expansion approach used |
| _optimizer_or_expansion_subheap | TRUE | Use subheap for optimizer or-expansion |
| _optimizer_order_by_elimination_enabled | TRUE | Eliminates order bys from views before query transformation |
| _optimizer_outer_to_anti_enabled | TRUE | Enable transformation of outer-join to anti-join if possible |
| _optimizer_percent_parallel | 101 | optimizer percent parallel |
| _optimizer_push_down_distinct | 0 | push down distinct from query block to table |
| _optimizer_push_pred_cost_based | TRUE | use cost-based query transformation for push pred optimization |
| _optimizer_random_plan | 0 | optimizer seed value for random plans |
| _optimizer_reuse_cost_annotations | TRUE | reuse cost annotations during cost-based query transformation |
| _optimizer_rownum_bind_default | 10 | Default value to use for rownum bind |
| _optimizer_rownum_pred_based_fkr | TRUE | enable the use of first K rows due to rownum predicate |
| _optimizer_save_stats | TRUE | enable/disable saving old versions of optimizer stats |
| _optimizer_search_limit | 5 | optimizer search limit |
| _optimizer_self_induced_cache_cost | FALSE | account for self-induced caching |
| _optimizer_skip_scan_enabled | TRUE | enable/disable index skip scan |
| _optimizer_skip_scan_guess | FALSE | consider index skip scan for predicates with guessed selectivity |
| _optimizer_sortmerge_join_enabled | TRUE | enable/disable sort-merge join method |
| _optimizer_sortmerge_join_inequality | TRUE | enable/disable sort-merge join using inequality predicates |
| _optimizer_squ_bottomup | TRUE | enables unnesting of subquery in a bottom-up manner |
| _optimizer_star_tran_in_with_clause | TRUE | enable/disable star transformation in with clause queries |
| _optimizer_star_trans_min_cost | 0 | optimizer star transformation minimum cost |
| _optimizer_star_trans_min_ratio | 0 | optimizer star transformation minimum ratio |
| _optimizer_starplan_enabled | TRUE | optimizer star plan enabled |
| _optimizer_system_stats_usage | TRUE | system statistics usage |
| _optimizer_trace | none | optimizer trace parameter |
| _optimizer_transitivity_retain | TRUE | retain equi-join pred upon transitive equality pred generation |
| _optimizer_undo_changes | FALSE | undo changes to query optimizer |
| _optimizer_undo_cost_change | 11.1.0.6 | optimizer undo cost change |
| _optimizer_use_subheap | TRUE | Enables physical optimizer subheap |
| _or_expand_nvl_predicate | TRUE | enable OR expanded plan for NVL/DECODE predicate |
| _oradbg_pathname | path of oradbg script | |
| _oradebug_force | FALSE | force target processes to execute oradebug commands? |
| _ordered_nested_loop | TRUE | enable ordered nested loop costing |
| _ordered_semijoin | TRUE | enable ordered semi-join subquery |
| _orph_cln_interval | 1200 | qmon periodic interval for removed subscriber messages cleanup |
| _os_sched_high_priority | 1 | OS high priority level |
| _other_wait_event_exclusion | exclude event names from _other_wait_threshold calculations | |
| _other_wait_threshold | 0 | threshold wait percentage for event wait class Other |
| _outline_bitmap_tree | TRUE | BITMAP_TREE hint enabled in outline |
| _parallel_adaptive_max_users | 2 | maximum number of users running with default DOP |
| _parallel_broadcast_enabled | TRUE | enable broadcasting of small inputs to hash and sort merge joins |
| _parallel_default_max_instances | 1 | default maximum number of instances for parallel query |
| _parallel_execution_message_align | FALSE | Alignment of PX buffers to OS page boundary |
| _parallel_fake_class_pct | 0 | fake db-scheduler percent used for testing |
| _parallel_fixwrite_bucket | 1000 | Number of buckets for each round of fix write |
| _parallel_load_bal_unit | 0 | number of threads to allocate per instance |
| _parallel_load_balancing | TRUE | parallel execution load balanced slave allocation |
| _parallel_min_message_pool | 206592 | minimum size of shared pool memory to reserve for pq servers |
| _parallel_policy | MANUAL | policy used to compute the degree of parallelism (MANUAL/LIMITED/AUTO) |
| _parallel_recovery_stopat | 32767 | stop at -position- to step through SMON |
| _parallel_replay_msg_limit | 4000 | Number of messages for each round of parallel replay |
| _parallel_server_idle_time | 30000 | idle time before parallel query server dies (in 1/100 sec) |
| _parallel_server_sleep_time | 10 | sleep time between dequeue timeouts (in 1/100ths) |
| _parallel_slave_acquisition_wait | 1 | time(in seconds) to wait before retrying slave acquisition |
| _parallel_time_threshold | 10 | threshold above which a plan is a candidate for parallelization (in seconds) |
| _parallel_time_unit | 10 | unit of work used to derive the degree of parallelism (in seconds) |
| _parallel_txn_global | FALSE | enable parallel_txn hint with updates and deletes |
| _parallelism_cost_fudge_factor | 350 | set the parallelism cost fudge factor |
| _parameter_table_block_size | 2048 | parameter table block size |
| _partial_pwise_join_enabled | TRUE | enable partial partition-wise join when TRUE |
| _partition_view_enabled | TRUE | enable/disable partitioned views |
| _passwordfile_enqueue_timeout | 900 | password file enqueue timeout in seconds |
| _pct_refresh_double_count_prevented | TRUE | materialized view PCT refreshes avoid double counting |
| _pdml_gim_sampling | 5000 | control separation of global index maintenance for PDML |
| _pdml_gim_staggered | FALSE | slaves start on different index when doing index maint |
| _pdml_slaves_diff_part | TRUE | slaves start on different partition when doing index maint |
| _percent_flashback_buf_partial_full | 50 | Percent of flashback buffer filled to be considered partial full |
| _pga_large_extent_size | 1048576 | PGA large extent size |
| _pga_max_size | 209715200 | Maximum size of the PGA memory for one process |
| _ping_level | 3 | fusion ping level |
| _pivot_implementation_method | CHOOSE | pivot implementation method |
| _pkt_enable | FALSE | enable progressive kill test |
| _pkt_pmon_interval | 50 | PMON process clean-up interval (cs) |
| _pkt_start | FALSE | start progressive kill test instrumention |
| _plan_outline_data | TRUE | explain plan outline data enabled |
| _plan_verify_improvement_margin | 150 | Performance improvement criterion for evolving plan baselines |
| _plan_verify_local_time_limit | 0 | Local time limit to use for an individual plan verification |
| _plsql_anon_block_code_type | INTERPRETED | PL/SQL anonymous block code-type |
| _plsql_cache_enable | TRUE | PL/SQL Function Cache Enabled |
| _plsql_dump_buffer_events | conditions upon which the PL/SQL circular buffer is dumped | |
| _plsql_minimum_cache_hit_percent | 20 | plsql minimum cache hit percentage required to keep caching active |
| _plsql_nvl_optimize | FALSE | PL/SQL NVL optimize |
| _pmon_load_constants | 300,192,64,3,10,10,0,0 | server load balancing constants (S,P,D,I,L,C,M) |
| _pre_rewrite_push_pred | TRUE | push predicates into views before rewrite |
| _precompute_gid_values | TRUE | precompute gid values and copy them before returning a row |
| _pred_move_around | TRUE | enables predicate move-around |
| _predicate_elimination_enabled | TRUE | allow predicate elimination if set to TRUE |
| _prescomm | FALSE | presume commit of IMU transactions |
| _print_refresh_schedule | false | enable dbms_output of materialized view refresh schedule |
| _private_memory_address | Start address of large extent memory segment | |
| _project_view_columns | TRUE | enable projecting out unreferenced columns of a view |
| _projection_pushdown | TRUE | projection pushdown |
| _projection_pushdown_debug | 0 | level for projection pushdown debugging |
| _prop_old_enabled | FALSE | Shift to pre 11g propagation behaviour |
| _protect_frame_heaps | FALSE | Protect cursor frame heaps |
| _push_join_predicate | TRUE | enable pushing join predicate inside a view |
| _push_join_union_view | TRUE | enable pushing join predicate inside a union all view |
| _push_join_union_view2 | TRUE | enable pushing join predicate inside a union view |
| _px_async_getgranule | FALSE | asynchronous get granule in the slave |
| _px_bind_peek_sharing | TRUE | enables sharing of px cursors that were built using bind peeking |
| _px_broadcast_fudge_factor | 100 | set the tq broadcasting fudge factor percentage |
| _px_buffer_ttl | 30 | ttl for px mesg buffers in seconds |
| _px_compilation_debug | 0 | debug level for parallel compilation |
| _px_compilation_trace | 0 | tracing level for parallel compilation |
| _px_dump_12805_source | TRUE | enables or disables tracing of 12805 signal source |
| _px_dynamic_opt | TRUE | turn off/on restartable qerpx dynamic optimization |
| _px_dynamic_sample_size | 50 | num of samples for restartable qerpx dynamic optimization |
| _px_execution_services_enabled | TRUE | enable service-based constraint of px slave allocation |
| _px_granule_size | 100000 | default size of a rowid range granule (in KB) |
| _px_index_sampling | 200 | parallel query sampling for index create (100000 = 100%) |
| _px_io_process_bandwidth | 200 | IO process bandwidth in MB/sec for computing DOP |
| _px_io_system_bandwidth | 0 | total IO system bandwidth in MB/sec for computing DOP |
| _px_kxib_tracing | 0 | turn on kxib tracing |
| _px_load_publish_interval | 200 | interval at which LMON will check whether to publish PX load |
| _px_loc_msg_cost | 1000 | CPU cost to send a PX message via shared memory |
| _px_max_granules_per_slave | 100 | maximum number of rowid range granules to generate per slave |
| _px_min_granules_per_slave | 13 | minimum number of rowid range granules to generate per slave |
| _px_minus_intersect | TRUE | enables pq for minus/interect operators |
| _px_net_msg_cost | 10000 | CPU cost to send a PX message over the internconnect |
| _px_no_granule_sort | FALSE | prevent parallel partition granules to be sorted on size |
| _px_no_stealing | FALSE | prevent parallel granule stealing in shared nothing environment |
| _px_nss_planb | TRUE | enables or disables NSS Plan B reparse with outline |
| _px_proc_constrain | TRUE | reduce parallel_max_servers if greater than (processes – fudge) |
| _px_pwg_enabled | TRUE | parallel partition wise group by enabled |
| _px_rownum_pd | TRUE | turn off/on parallel rownum pushdown optimization |
| _px_send_timeout | 300 | IPC message send timeout value in seconds |
| _px_slaves_share_cursors | 0 | slaves share cursors with QC |
| _px_trace | none | px trace parameter |
| _px_ual_serial_input | TRUE | enables new pq for UNION operators |
| _px_xtgranule_size | 10000 | default size of a external table granule (in KB) |
| _qa_control | 0 | Oracle internal parameter to control QA |
| _qa_lrg_type | 0 | Oracle internal parameter to specify QA lrg type |
| _query_cost_rewrite | TRUE | perform the cost based rewrite with materialized views |
| _query_execution_cache_max_size | 65536 | max size of query execution cache |
| _query_mmvrewrite_maxcmaps | 20 | query mmv rewrite maximum number of cmaps per dmap in query disjunct |
| _query_mmvrewrite_maxdmaps | 10 | query mmv rewrite maximum number of dmaps per query disjunct |
| _query_mmvrewrite_maxinlists | 5 | query mmv rewrite maximum number of in-lists per disjunct |
| _query_mmvrewrite_maxintervals | 5 | query mmv rewrite maximum number of intervals per disjunct |
| _query_mmvrewrite_maxmergedcmaps | 50 | query mmv rewrite maximum number of merged cmaps |
| _query_mmvrewrite_maxpreds | 10 | query mmv rewrite maximum number of predicates per disjunct |
| _query_mmvrewrite_maxqryinlistvals | 500 | query mmv rewrite maximum number of query in-list values |
| _query_mmvrewrite_maxregperm | 512 | query mmv rewrite maximum number of region permutations |
| _query_rewrite_1 | TRUE | perform query rewrite before&after or only before view merging |
| _query_rewrite_2 | TRUE | perform query rewrite before&after or only after view merging |
| _query_rewrite_drj | TRUE | mv rewrite and drop redundant joins |
| _query_rewrite_expression | TRUE | rewrite with cannonical form for expressions |
| _query_rewrite_fpc | TRUE | mv rewrite fresh partition containment |
| _query_rewrite_fudge | 90 | cost based query rewrite with MVs fudge factor |
| _query_rewrite_jgmigrate | TRUE | mv rewrite with jg migration |
| _query_rewrite_maxdisjunct | 257 | query rewrite max disjuncts |
| _query_rewrite_or_error | FALSE | allow query rewrite, if referenced tables are not dataless |
| _query_rewrite_setopgrw_enable | TRUE | perform general rewrite using set operator summaries |
| _query_rewrite_vop_cleanup | TRUE | prune frocol chain before rewrite after view-merging |
| _rcfg_parallel_fixwrite | TRUE | if TRUE enables parallel fixwrite at reconfiguration |
| _rcfg_parallel_replay | TRUE | if TRUE enables parallel replay and cleanup at reconfiguration |
| _rcfg_parallel_verify | TRUE | if TRUE enables parallel verify at reconfiguration |
| _rdbms_compatibility | 10.1 | default RDBMS compatibility level |
| _rdbms_internal_fplib_enabled | FALSE | enable SAGE FPLIB filtering within rdbms |
| _rdbms_internal_fplib_raise_errors | FALSE | enable reraising of any exceptions in SAGE FPLIB |
| _readable_standby_mode | SLFLUSH | readable standby mode |
| _readable_standby_sync_timeout | 10 | readable standby query scn sync timeout |
| _real_time_apply_sim | 0 | Simulation value with real time apply |
| _realfree_heap_max_size | 32768 | minimum max total heap size, in Kbytes |
| _realfree_heap_mode | 0 | mode flags for real-free heap |
| _realfree_heap_pagesize_hint | 65536 | hint for real-free page size in bytes |
| _recoverable_recovery_batch_percent | 50 | Recoverable recovery batch size (percentage of buffer cache) |
| _recovery_asserts | FALSE | if TRUE, enable expensive integrity checks |
| _recovery_percentage | 50 | recovery buffer cache percentage |
| _recovery_verify_writes | FALSE | enable thread recovery write verify |
| _recursive_imu_transactions | FALSE | recursive transactions may be IMU |
| _redo_compatibility_check | FALSE | general and redo/undo compatibility sanity check |
| _redo_read_from_memory | TRUE | Enable reading redo from memory |
| _redo_transport_compress_all | FALSE | Is ASYNC LNS compression allowed? |
| _release_insert_threshold | 5 | maximum number of unusable blocks to unlink from freelist |
| _reliable_block_sends | FALSE | if TRUE, block sends across interconnect are reliable |
| _remove_aggr_subquery | TRUE | enables removal of subsumed aggregated subquery |
| _replace_virtual_columns | TRUE | replace expressions with virtual columns |
| _resource_manager_always_off | FALSE | disable the resource manager always |
| _resource_manager_always_on | TRUE | enable the resource manager always |
| _restore_spfile | restore spfile to this location | |
| _result_cache_auto_execution_threshold | 1 | result cache auto execution threshold |
| _result_cache_auto_size_threshold | 100 | result cache auto max size allowed |
| _result_cache_auto_time_distance | 300 | result cache auto time distance |
| _result_cache_auto_time_threshold | 1000 | result cache auto time threshold |
| _result_cache_block_size | 1024 | result cache block size |
| _result_cache_timeout | 60 | maximum time (sec) a session waits for a result |
| _reuse_index_loop | 5 | number of blocks being examine for index block reuse |
| _right_outer_hash_enable | TRUE | Right Outer/Semi/Anti Hash Enabled |
| _rman_io_priority | 3 | priority at which rman backup i/o’s are done |
| _rman_restore_through_link | FALSE | RMAN restore through link |
| _rollback_segment_count | 0 | number of undo segments |
| _rollback_segment_initial | 1 | starting undo segment number |
| _rollback_stopat | 0 | stop at -position to step rollback |
| _row_cache_cursors | 20 | number of cached cursors for row cache management |
| _row_cr | TRUE | enable row cr for all sql |
| _row_locking | always | row-locking |
| _row_shipping_explain | FALSE | enable row shipping explain plan support |
| _row_shipping_threshold | 80 | row shipping column selection threshold |
| _rowsource_execution_statistics | FALSE | if TRUE, Oracle will collect rowsource statistics |
| _rowsource_profiling_statistics | TRUE | if TRUE, Oracle will capture active row sources in v$active_session_history |
| _rowsource_statistics_sampfreq | 128 | frequency of rowsource statistic sampling (must be a power of 2) |
| _rowsrc_trace_level | 0 | Row source tree tracing level |
| _rtc_infeasible_threshold | 10 | Redo Transport Compression infeasible threshold |
| _sage_enabled | 1 | enable real SAGE functionality |
| _sage_fcre | TRUE | Allow optimized file creation path for SAGE |
| _sample_rows_per_block | 4 | number of rows per block used for sampling IO optimization |
| _scatter_gcs_resources | FALSE | if TRUE, gcs resources are scattered uniformly across sub pools |
| _scatter_gcs_shadows | FALSE | if TRUE, gcs shadows are scattered uniformly across sub pools |
| _scn_wait_interface_max_backoff_time_secs | 600 | max exponential backoff time for scn wait interface in kta |
| _scn_wait_interface_max_timeout_secs | 2147483647 | max timeout for scn wait interface in kta |
| _sdiag_crash | NONE | sql diag crash |
| _sec_enable_test_rpcs | FALSE | Whether to enable the test RPCs |
| _second_spare_parameter | second spare parameter – integer | |
| _securefile_timers | FALSE | collect kdlu timers and accumulate per layers |
| _selectivity_for_srf_enabled | FALSE | enable/disable selectivity for storage reduction factor |
| _selfjoin_mv_duplicates | TRUE | control rewrite self-join algorithm |
| _selftune_checkpoint_write_pct | 3 | Percentage of total physical i/os for self-tune ckpt |
| _selftune_checkpointing_lag | 300 | Self-tune checkpointing lag the tail of the redo log |
| _send_ast_to_foreground | TRUE | if TRUE, send ast message to foreground |
| _send_close_with_block | TRUE | if TRUE, send close with block even with direct sends |
| _send_requests_to_pi | TRUE | if TRUE, try to send CR requests to PI buffers |
| _serial_direct_read | FALSE | enable direct read in serial |
| _serial_recovery | FALSE | force serial recovery or parallel recovery |
| _serializable | FALSE | serializable |
| _session_cached_instantiations | 60 | Number of pl/sql instantiations to cache in a session. |
| _session_context_size | 10000 | session app context size |
| _session_idle_bit_latches | 0 | one latch per session or a latch per group of sessions |
| _session_idle_check_interval | 60 | Resource Manager session idle limit check interval in seconds |
| _session_kept_cursor_pins | 0 | Number of cursors pins to keep in a session |
| _session_wait_history | 10 | enable session wait history collection |
| _seventh_spare_parameter | seventh spare parameter – string list | |
| _sga_clear_dump | FALSE | Allow dumping encrypted blocks in clear for debugging |
| _sga_early_trace | 0 | sga early trace event |
| _sga_locking | none | sga granule locking state |
| _shared_io_pool_buf_size | 1048576 | Shared IO pool buffer size |
| _shared_io_pool_debug_trc | 0 | trace kcbi debug info to tracefile |
| _shared_io_pool_size | 0 | Size of shared IO pool |
| _shared_io_set_value | FALSE | shared io pool size set internal value – overwrite zero user size |
| _shared_iop_max_size | 536870912 | maximum shared io pool size |
| _shared_pool_max_size | 0 | shared pool maximum size when auto SGA enabled |
| _shared_pool_minsize_on | FALSE | shared pool minimum size when auto SGA enabled |
| _shared_pool_reserved_min_alloc | 4400 | minimum allocation size in bytes for reserved area of shared pool |
| _shared_pool_reserved_pct | 5 | percentage memory of the shared pool allocated for the reserved area |
| _shared_server_load_balance | 0 | shared server load balance |
| _shared_server_num_queues | 1 | number of shared server common queues |
| _short_stack_timeout_ms | 30000 | short stack timeout in ms |
| _shrunk_aggs_disable_threshold | 60 | percentage of exceptions at which to switch to full length aggs |
| _shrunk_aggs_enabled | TRUE | enable use of variable sized buffers for non-distinct aggregates |
| _side_channel_batch_size | 200 | number of messages to batch in a side channel message (DFS) |
| _side_channel_batch_timeout | 6 | timeout before shipping out the batched side channelmessages in seconds |
| _side_channel_batch_timeout_ms | 500 | timeout before shipping out the batched side channelmessages in milliseconds |
| _simple_view_merging | TRUE | control simple view merging performed by the optimizer |
| _simulate_mem_transfer | FALSE | simulate auto memory sga/pga transfers |
| _simulator_bucket_mindelta | 8192 | LRU bucket minimum delta |
| _simulator_internal_bound | 10 | simulator internal bound percent |
| _simulator_lru_rebalance_sizthr | 5 | LRU list rebalance threshold (size) |
| _simulator_lru_rebalance_thresh | 10240 | LRU list rebalance threshold (count) |
| _simulator_lru_scan_count | 8 | LRU scan count |
| _simulator_pin_inval_maxcnt | 16 | maximum count of invalid chunks on pin list |
| _simulator_reserved_heap_count | 4096 | simulator reserved heap count |
| _simulator_reserved_obj_count | 1024 | simulator reserved object count |
| _simulator_sampling_factor | 2 | sampling factor for the simulator |
| _simulator_upper_bound_multiple | 2 | upper bound multiple of pool size |
| _single_process | FALSE | run without detached processes |
| _siop_flashback_scandepth | 20 | Shared IO pool flashback io completion scan depth |
| _sixth_spare_parameter | sixth spare parameter – string list | |
| _skgxp_reaping | 1000 | tune skgxp OSD reaping limit |
| _skgxp_udp_ach_reaping_time | 120 | time in minutes before idle ach’s are reaped |
| _skgxp_udp_ack_delay | 0 | Enables delayed acks |
| _skgxp_udp_enable_dynamic_credit_mgmt | 0 | Enables dynamic credit management |
| _skgxp_udp_hiwat_warn | 1000 | ach hiwat mark warning interval |
| _skgxp_udp_interface_detection_time_secs | 60 | time in seconds between interface detection checks |
| _skgxp_udp_keep_alive_ping_timer_secs | 300 | connection idle time in seconds before keep alive is initiated. min: 30 sec max: 1800 sec default: 300 sec |
| _skgxp_udp_lmp_mtusize | 0 | MTU size for UDP LMP testing |
| _skgxp_udp_lmp_on | FALSE | enable UDP long message protection |
| _skgxp_udp_timed_wait_buffering | 1024 | diagnostic log buffering space (in bytes) for timed wait (0 means unbufferd |
| _skgxp_udp_timed_wait_seconds | 5 | time in seconds before timed wait is invoked |
| _skgxp_udp_use_tcb | TRUE | disable use of high speek timer |
| _skip_assume_msg | TRUE | if TRUE, skip assume message for consigns at the master |
| _slave_mapping_enabled | TRUE | enable slave mapping when TRUE |
| _slave_mapping_group_size | 0 | force the number of slave group in a slave mapper |
| _small_table_threshold | 541 | threshold level of table size for direct reads |
| _smm_advice_enabled | TRUE | if TRUE, enable v$pga_advice |
| _smm_advice_log_size | 0 | overwrites default size of the PGA advice workarea history log |
| _smm_auto_cost_enabled | TRUE | if TRUE, use the AUTO size policy cost functions |
| _smm_auto_max_io_size | 248 | Maximum IO size (in KB) used by sort/hash-join in auto mode |
| _smm_auto_min_io_size | 56 | Minimum IO size (in KB) used by sort/hash-join in auto mode |
| _smm_bound | 0 | overwrites memory manager automatically computed bound |
| _smm_control | 0 | provides controls on the memory manager |
| _smm_freeable_retain | 5120 | value in KB of the instance freeable PGA memory to retain |
| _smm_isort_cap | 102400 | maximum work area for insertion sort(v1) |
| _smm_max_size | 40960 | maximum work area size in auto mode (serial) |
| _smm_min_size | 204 | minimum work area size in auto mode |
| _smm_px_max_size | 102400 | maximum work area size in auto mode (global) |
| _smm_retain_size | 0 | work area retain size in SGA for shared server sessions (0 for AUTO) |
| _smm_trace | 0 | Turn on/off tracing for SQL memory manager |
| _smon_internal_errlimit | 100 | limit of SMON internal errors |
| _smon_undo_seg_rescan_limit | 10 | limit of SMON continous undo segments re-scan |
| _smu_debug_mode | 0 | - set debug event for testing SMU operations |
| _smu_error_simulation_site | 0 | site ID of error simulation in KTU code |
| _smu_error_simulation_type | 0 | error type for error simulation in KTU code |
| _smu_timeouts | comma-separated *AND double-quoted* list of AUM timeouts: mql, tur, sess_exprn, qry_exprn, slot_intvl | |
| _sort_elimination_cost_ratio | 0 | cost ratio for sort eimination under first_rows mode |
| _sort_multiblock_read_count | 2 | multi-block read count for sort |
| _space_align_size | 1048576 | space align size |
| _spin_count | 1 | Amount to spin waiting for a latch |
| _spr_max_rules | 10000 | maximum number of rules in sql spreadsheet |
| _spr_push_pred_refspr | TRUE | push predicates through reference spreadsheet |
| _spr_use_AW_AS | TRUE | enable AW for hash table in spreadsheet |
| _spr_use_hash_table | FALSE | use hash table for spreadsheet |
| _sql_analyze_parse_model | 2 | SQL Analyze Parse Model control parameter |
| _sql_connect_capability_override | 0 | SQL Connect Capability Table Override |
| _sql_connect_capability_table | SQL Connect Capability Table (testing only) | |
| _sql_hash_debug | 0 | Hash value of the SQL statement to debug |
| _sql_model_unfold_forloops | RUN_TIME | specifies compile-time unfolding of sql model forloops |
| _sql_plan_baseline_capture_on_1_exec | FALSE | With auto-capture on, create new SQL plan baseline on first exec |
| _sqlexec_progression_cost | 1000 | sql execution progression monitoring cost threshold |
| _sqlmon_max_plan | 20 | Maximum number of plans entry that can be monitored. Defaults to 20 per CPU |
| _sqlmon_max_planlines | 300 | Number of plan lines beyond which a plan cannot be monitored |
| _sqlmon_threshold | 5 | CPU/IO time threshold before a statement is monitored. 0 is disabled |
| _sqltune_category_parsed | DEFAULT | Parsed category qualifier for applying hintsets |
| _srvntfn_job_deq_timeout | 60 | srvntfn job deq timeout |
| _srvntfn_jobsubmit_interval | 3 | srvntfn job submit interval |
| _srvntfn_max_concurrent_jobs | 20 | srvntfn max concurrent jobs |
| _srvntfn_q_msgcount | 50 | srvntfn q msg count for job exit |
| _srvntfn_q_msgcount_inc | 100 | srvntfn q msg count increase for job submit |
| _sscr_dir | Session State Capture and Restore DIRectory object | |
| _sscr_osdir | Session State Capture and Restore OS DIRectory | |
| _sta_control | 0 | SQL Tuning Advisory control parameter |
| _stack_guard_level | 0 | stack guard level |
| _static_backgrounds | static backgrounds | |
| _statistics_based_srf_enabled | TRUE | enable/disable the use of statistics for storage reduction factor |
| _step_down_limit_in_pct | 1 | step down limit in percentage |
| _stn_trace | 0 | SQL tracing parameter |
| _storage_predicate_access_predicate | 0 | put storage predicate into access predicate in explain plan |
| _streams_pool_max_size | 0 | streams pool maximum size when auto SGA enabled |
| _subquery_pruning_cost_factor | 20 | subquery pruning cost factor |
| _subquery_pruning_enabled | TRUE | enable the use of subquery predicates to perform pruning |
| _subquery_pruning_mv_enabled | FALSE | enable the use of subquery predicates with MVs to perform pruning |
| _subquery_pruning_reduction | 50 | subquery pruning reduction factor |
| _swrf_metric_frequent_mode | FALSE | Enable/disable SWRF Metric Frequent Mode Collection |
| _swrf_mmon_dbfus | TRUE | Enable/disable SWRF MMON DB Feature Usage |
| _swrf_mmon_flush | TRUE | Enable/disable SWRF MMON FLushing |
| _swrf_mmon_metrics | TRUE | Enable/disable SWRF MMON Metrics Collection |
| _swrf_on_disk_enabled | TRUE | Parameter to enable/disable SWRF |
| _swrf_test_action | 0 | test action parameter for SWRF |
| _swrf_test_dbfus | FALSE | Enable/disable DB Feature Usage Testing |
| _synonym_repoint_tracing | FALSE | whether to trace metadata comparisons for synonym repointing |
| _sysaux_test_param | 1 | test parameter for SYSAUX |
| _system_index_caching | 0 | optimizer percent system index caching |
| _system_trig_enabled | TRUE | are system triggers enabled |
| _ta_lns_wait_for_arch_log | 20 | LNS Wait time for arhcived version of online log |
| _table_lookup_prefetch_size | 40 | table lookup prefetch vector size |
| _table_lookup_prefetch_thresh | 2 | table lookup prefetch threshold |
| _table_scan_cost_plus_one | TRUE | bump estimated full table scan and index ffs cost by one |
| _target_rba_max_lag_percentage | 90 | target rba max log lag percentage |
| _tdb_debug_mode | 16 | set debug mode for testing transportable database |
| _temp_tran_block_threshold | 100 | number of blocks for a dimension before we temp transform |
| _temp_tran_cache | TRUE | determines if temp table is created with cache option |
| _test_ksusigskip | 5 | test the function ksusigskip |
| _test_param_1 | 25 | test parmeter 1 – integer |
| _test_param_2 | test parameter 2 – string | |
| _test_param_3 | test parameter 3 – string | |
| _test_param_4 | test parameter 4 – string list | |
| _test_param_5 | 25 | test parmeter 5 – deprecated integer |
| _test_param_6 | 0 | test parmeter 6 – size (ub8) |
| _test_spacebg | 0 | test space management background task |
| _third_spare_parameter | third spare parameter – integer | |
| _threshold_alerts_enable | 1 | if 1, issue threshold-based alerts |
| _timemodel_collection | TRUE | enable timemodel collection |
| _timeout_actions_enabled | TRUE | enables or disables KSU timeout actions |
| _timer_precision | 20 | VKTM sleep time in milli-sec |
| _total_large_extent_memory | 0 | Total memory for allocating large extents |
| _tq_dump_period | 0 | time period for duping of TQ statistics (s) |
| _trace_buffer_wait_timeouts | 0 | trace buffer busy wait timeouts |
| _trace_buffers | ALL:256 | trace buffer sizes per process |
| _trace_dump_all_procs | FALSE | if TRUE on error buckets of all processes will be dumped to the current trace file |
| _trace_dump_client_buckets | TRUE | if TRUE dump client (ie. non-kst) buckets |
| _trace_dump_cur_proc_only | FALSE | if TRUE on error just dump our process bucket |
| _trace_dump_static_only | FALSE | if TRUE filter trace dumps to always loaded dlls |
| _trace_events | trace events enabled at startup | |
| _trace_files_public | FALSE | Create publicly accessible trace files |
| _trace_kqlidp | FALSE | trace kqlidp0 operation |
| _trace_navigation_scope | global | enabling trace navigation linking |
| _trace_pin_time | 0 | trace how long a current pin is held |
| _trace_pool_size | trace pool size in bytes | |
| _trace_processes | ALL | enable KST tracing in process |
| _trace_virtual_columns | FALSE | trace virtual columns exprs |
| _transaction_auditing | TRUE | transaction auditing records generated in the redo log |
| _transaction_recovery_servers | 0 | max number of parallel recovery slaves that may be used |
| _truncate_optimization_enabled | TRUE | do truncate optimization if set to TRUE |
| _tsenc_tracing | 0 | Enable TS encryption tracing |
| _tsm_connect_string | TSM test connect string | |
| _tsm_disable_auto_cleanup | 1 | Disable TSM auto cleanup actions |
| _tts_allow_charset_mismatch | FALSE | allow plugging in a tablespace with an incompatible character set |
| _two_pass | TRUE | enable two-pass thread recovery |
| _two_pass_reverse_polish_enabled | TRUE | uses two-pass reverse polish alg. to generate canonical forms |
| _uga_cga_large_extent_size | 262144 | UGA/CGA large extent size |
| _ultrafast_latch_statistics | TRUE | maintain fast-path statistics for ultrafast latches |
| _undo_autotune | TRUE | enable auto tuning of undo_retention |
| _undo_block_compression | TRUE | enable undo block compression |
| _undo_debug_mode | 0 | debug flag for undo related operations |
| _undo_debug_usage | 0 | invoke undo usage functions for testing |
| _union_rewrite_for_gs | YES_GSET_MVS | expand queries with GSets into UNIONs for rewrite |
| _unnest_subquery | TRUE | enables unnesting of correlated subqueries |
| _unused_block_compression | TRUE | enable unused block compression |
| _update_datafile_headers_with_space_information | FALSE | user requested update of datafile headers of locally managed datafiles with space information |
| _use_best_fit | FALSE | use best fit to allocate space |
| _use_column_stats_for_function | TRUE | enable the use of column statistics for DDP functions |
| _use_ism | TRUE | Enable Shared Page Tables – ISM |
| _use_ism_for_pga | TRUE | Use ISM for allocating large extents |
| _use_nosegment_indexes | FALSE | use nosegment indexes in explain plan |
| _use_realfree_heap | TRUE | use real-free based allocator for PGA memory |
| _use_seq_process_cache | TRUE | whether to use process local seq cache |
| _use_vector_post | TRUE | use vector post |
| _use_zero_copy_io | TRUE | Should network vector IO interface be used for data transfer |
| _validate_flashback_database | FALSE | Scan database to validate result of flashback database |
| _vendor_lib_loc | Vendor library search root directory | |
| _verify_flashback_redo | TRUE | Verify that the redo logs needed for flashback are available |
| _verify_undo_quota | FALSE | TRUE – verify consistency of undo quota statistics |
| _very_large_partitioned_table | 1024 | very_large_partitioned_table |
| _virtual_column_overload_allowed | TRUE | overload virtual columns expression |
| _wait_breakup_threshold_csecs | 600 | Wait breakup threshold (in centiseconds) |
| _wait_breakup_time_csecs | 300 | Wait breakup time (in centiseconds) |
| _wait_for_sync | TRUE | wait for sync on commit MUST BE ALWAYS TRUE |
| _walk_insert_threshold | 0 | maximum number of unusable blocks to walk across freelist |
| _watchpoint_on | FALSE | is the watchpointing feature turned on? |
| _wcr_control | 0 | Oracle internal test WCR parameter used ONLY for testing! |
| _windowfunc_optimization_settings | 0 | settings for window function optimizations |
| _with_subquery | OPTIMIZER | WITH subquery transformation |
| _write_clones | 3 | write clones flag |
| _xpl_peeked_binds_log_size | 8192 | maximum bytes for logging peeked bind values for V$SQL_PLAN (0 = OFF) |
| _xpl_trace | 0 | Explain Plan tracing parameter |
| _xsolapi_auto_materialization_bound | 20 | OLAP API lower bound for auto materialization. |
| _xsolapi_auto_materialization_type | PRED_AND_RC | OLAP API behavior for auto materialization |
| _xsolapi_build_trace | FALSE | OLAP API output build info to trace file |
| _xsolapi_debug_output | SUPPRESS | OLAP API debug output disposition |
| _xsolapi_densify_cubes | TABULAR | OLAP API cube densification |
| _xsolapi_dimension_group_creation | OVERFETCH | OLAP API symmetric overfetch |
| _xsolapi_dml_trace | FALSE | OLAP API output dml commands and expressions to trace file |
| _xsolapi_fetch_type | PARTIAL | OLAP API fetch type |
| _xsolapi_fix_vptrs | FALSE | OLAP API Enable vptr fixing logic in shared server mode |
| _xsolapi_generate_with_clause | FALSE | OLAP API generates WITH clause? |
| _xsolapi_hierarchy_value_type | unique | OLAP API hierarchy value type |
| _xsolapi_load_at_process_start | NEVER | When to load OLAP API library at server process start |
| _xsolapi_materialization_rowcache_min_rows_for_use | 1 | OLAP API min number of rows required to use rowcache in query materialization |
| _xsolapi_materialize_sources | TRUE | OLAP API Enable source materialization |
| _xsolapi_metadata_reader_mode | 11_ONLY | OLAP API metadata reader mode |
| _xsolapi_odbo_mode | FALSE | OLAP API uses ODBO mode? |
| _xsolapi_opt_aw_position | TRUE | OLAP API enables AW position and count optimization? |
| _xsolapi_optimize_suppression | TRUE | OLAP API optimizes suppressions? |
| _xsolapi_precompute_subquery | TRUE | OLAP API precomputes subqueries? |
| _xsolapi_remove_columns_for_materialization | TRUE | OLAP API removes columns for materialization? |
| _xsolapi_set_nls | TRUE | OLAP API sets NLS? |
| _xsolapi_share_executors | TRUE | OLAP API share executors? |
| _xsolapi_source_trace | FALSE | OLAP API output Source definitions to trace file |
| _xsolapi_sql_all_multi_join_non_base_hints | OLAP API multi-join non-base hints | |
| _xsolapi_sql_all_non_base_hints | OLAP API non-base hints | |
| _xsolapi_sql_auto_dimension_hints | FALSE | OLAP API enable automatic dimension hints |
| _xsolapi_sql_auto_measure_hints | TRUE | OLAP API enable automatic measure hints |
| _xsolapi_sql_dimension_hints | OLAP API dimension hints | |
| _xsolapi_sql_enable_aw_join | TRUE | OLAP API enables AW join? |
| _xsolapi_sql_enable_aw_qdr_merge | TRUE | OLAP API enables AW QDR merge? |
| _xsolapi_sql_hints | OLAP API generic hints | |
| _xsolapi_sql_measure_hints | OLAP API measure hints | |
| _xsolapi_sql_minus_threshold | 1000 | OLAP API SQL MINUS threshold |
| _xsolapi_sql_optimize | TRUE | OLAP API enable optimization |
| _xsolapi_sql_prepare_stmt_cache_size | 16 | OLAP API prepare statement cache size |
| _xsolapi_sql_remove_columns | TRUE | OLAP API enable remove unused columns optimizations |
| _xsolapi_sql_result_set_cache_size | 32 | OLAP API result set cache size |
| _xsolapi_sql_symmetric_predicate | TRUE | OLAP API enable symmetric predicate for dimension groups |
| _xsolapi_sql_top_dimension_hints | OLAP API top dimension hints | |
| _xsolapi_sql_top_measure_hints | OLAP API top measure hints | |
| _xsolapi_sql_use_bind_variables | TRUE | OLAP API enable bind variables optimization |
| _xsolapi_stringify_order_levels | FALSE | OLAP API stringifies order levels? |
| _xsolapi_support_mtm | FALSE | OLAP API MTM mapping classes supported? |
| _xsolapi_suppression_aw_mask_threshold | 1000 | OLAP API suppression AW mask threshold |
| _xsolapi_suppression_chunk_size | 4000 | OLAP API suppression chunk size |
| _xsolapi_use_models | TRUE | OLAP API uses models? |
| _xsolapi_use_olap_dml | TRUE | OLAP API uses OLAP DML? |
| _xsolapi_use_olap_dml_for_rank | TRUE | OLAP API uses OLAP DML for rank? |
| _xt_coverage | none | external tables code coverage parameter |
| _xt_trace | none | external tables trace parameter |
| _xtbuffer_size | 0 | buffer size in KB needed for populate/query operation |
| _xtts_allow_pre10 | FALSE | allow cross platform for pre10 compatible tablespace |
| _xtts_set_platform_info | FALSE | set cross platform info during file header read |
| _yield_check_interval | 100000 | interval to check whether actses should yield |