使用该脚本可收集与undo相关的信息，在undo表空间出问题时可使用该脚本来诊断。
使用方法：
1.将脚本拷贝到服务器，创建文件保存，文件名可随意取，例如：diag.out
2.以sys用户登录数据库，执行脚本。执行方式为：
SQL> @diag.out
spool Undo_Diag.out ttitle off set pages 999 set lines 150 set verify off set termout off set trimout on set trimspool on REM REM ------------------------------------------------------------------------ REM REM ----------------------------------------------------------------- REM set space 2 REM REPORTING TABLESPACE INFORMATION: REM REM This looks at Tablespace Sizing - Total bytes and free bytes REM column tablespace_name format a30 heading 'TS Name' column sbytes format 9,999,999,999 heading 'Total MBytes' column fbytes format 9,999,999,999 heading 'Free MBytes' column file_name format a30 heading 'File Name' column kount format 999 heading 'Ext' compute sum of fbytes on tablespace_name compute sum of sbytes on tablespace_name compute sum of sbytes on report compute sum of fbytes on report break on tablespace_name skip 2 select a.tablespace_name, a.file_name, round(a.bytes/1024/1024,0) sbytes, round(sum(b.bytes/1024/1024),0) fbytes, count(*) kount, autoextensible from dba_data_files a, dba_free_space b where a.file_id = b.file_id and a.tablespace_name in (select z.tablespace_name from dba_tablespaces z where retention like '%GUARANTEE') group by a.tablespace_name, a.file_name, a.bytes, autoextensible order by a.tablespace_name / set linesize 160 REM REM If you can significantly reduce physical reads by adding incremental REM data buffers...do it. To determine whether adding data buffers will REM help, set db_block_lru_statistics = TRUE and REM db_block_lru_extended_statistics = TRUE in the init.ora parameters. REM You can determine how many extra hits you would get from memory as REM opposed to physical I/O from disk. **NOTE: Turning these on will REM impact performance. One shift of statistics gathering should be enough REM to get the required information. REM REM REM ----------------------------------------------------------------- REM set lines 160 col tablespace_name format a30 heading "Tablespace" col tb format a15 heading "TB Status" col df format a10 heading "DF Status" col extent_management format a15 heading "Extent|Management" col allocation_type format a8 heading "Type" col segment_space_management format a7 heading "Auto|Segment" col retention format a11 heading "Retention|Level" col autoextensible format a5 heading "Auto?" col mx format 999,999,999 heading "Max Allowed" select t.tablespace_name, t.status tb, d.status df, extent_management, allocation_type, segment_space_management, retention, autoextensible, (maxbytes/1024/1024) mx from dba_tablespaces t, dba_data_files d where t.tablespace_name = d.tablespace_name and retention like '%GUARANTEE' / col status format a20 head "Status" col cnt format 999,999,999 head "How Many?" select status, count(*) cnt from dba_rollback_segs group by status / set termout on set trimout off set trimspool off set lines 120 set pages 999 set termout off set trimout on set trimspool on alter session set nls_date_format='dd-Mon-yyyy hh24:mi'; prompt prompt ############## RUNTIME ############## prompt col rdate head "Run Time" select sysdate rdate from dual; prompt prompt ############## DATAFILES ############## prompt col retention head "Retention" col tablespace_name format a30 head "TBSP Name" col file_id format 999 head "File #" col a format 999,999,999,999,999 head "Bytes Alloc (MB)" col b format 999,999,999,999,999 head "Max Bytes Used (MB)" col autoextensible head "Auto|Ext" col extent_management head "Ext Mngmnt" col allocation_type head "Type" col segment_space_management head "SSM" select tablespace_name, file_id, sum(bytes)/1024/1024 a, sum(maxbytes)/1024/1024 b, autoextensible from dba_data_files where tablespace_name in (select tablespace_name from dba_tablespaces where retention like '%GUARANTEE' ) group by file_id, tablespace_name, autoextensible order by tablespace_name / set termout on set trimout off set trimspool off ttitle off set pages 999 set lines 150 set verify off set termout off set trimout on set trimspool on REM REM ------------------------------------------------------------------------ REM REM ----------------------------------------------------------------- REM REM REM REPORTING UNDO EXTENTS INFORMATION: REM REM ----------------------------------------------------------------- REM REM Undo Extents breakdown information REM ttitle center "Rollback Segments Breakdown" skip 2 col status format a20 col cnt format 999,999,999 head "How Many?" select status, count(*) cnt from dba_rollback_segs group by status / ttitle center "Undo Extents" skip 2 col segment_name format a30 heading "Name" col "ACT BYTES" format 999,999,999,999 head "Active|Extents" col "UNEXP BYTES" format 999,999,999,999 head "Unxpired|Extents" col "EXP BYTES" format 999,999,999,999 head "Expired|Extents" select segment_name, nvl(sum(act),0) "ACT BYTES", nvl(sum(unexp),0) "UNEXP BYTES", nvl(sum(exp),0) "EXP BYTES" from ( select segment_name, nvl(sum(bytes),0) act,00 unexp, 00 exp from DBA_UNDO_EXTENTS where status='ACTIVE' group by segment_name union select segment_name, 00 act, nvl(sum(bytes),0) unexp, 00 exp from DBA_UNDO_EXTENTS where status='UNEXPIRED' group by segment_name union select segment_name, 00 act, 00 unexp, nvl(sum(bytes),0) exp from DBA_UNDO_EXTENTS where status='EXPIRED' group by segment_name ) group by segment_name; ttitle center "Undo Extents Statistics" skip 2 col size format 999,999,999,999 heading "Size" col "HOW MANY" format 999,999,999 heading "How Many?" col st heading a12 heading "Status" select distinct status st, count(*) "HOW MANY", sum(bytes) "SIZE" from dba_undo_extents group by status / col segment_name format a30 heading "Name" col TABLESPACE_NAME for a20 col BYTES for 999,999,999,999 col BLOCKS for 999,999,999 col status for a15 heading "Status" col segment_name heading "Segment" col extent_id heading "ID" select SEGMENT_NAME, TABLESPACE_NAME, EXTENT_ID, FILE_ID, BLOCK_ID, BYTES, BLOCKS, STATUS from dba_undo_extents order by 1,3,4,5 / REM REM ----------------------------------------------------------------- REM REM Undo Extents Contention breakdown REM Take out column TUNED_UNDORETENTION if customer REM prior to 10.2.x REM REM The time frame can be adjusted with this query REM By default using around 4 hour window of time REM REM Ex. REM Using sysdate-.04 looking at the last hour REM Using sysdate-.16 looking at the last 4 hours REM Using sysdate-.32 looking at the last 8 hours REM Using sysdate-1 looking at the last 24 hours REM set linesize 140 ttitle center "Undo Extents Error Conditions (Default - Last 4 Hours)" skip 2 col UNXPSTEALCNT format 999,999,999 heading "# Unexpired|Stolen" col EXPSTEALCNT format 999,999,999 heading "# Expired|Reused" col SSOLDERRCNT format 999,999,999 heading "ORA-1555|Error" col NOSPACEERRCNT format 999,999,999 heading "Out-Of-space|Error" col MAXQUERYLEN format 999,999,999 heading "Max Query|Length" col TUNED_UNDORETENTION format 999,999,999 heading "Auto-Ajusted|Undo Retention" col hours format 999,999 heading "Tuned|(HRs)" select inst_id, to_char(begin_time,'MM/DD/YYYY HH24:MI') begin_time, UNXPSTEALCNT, EXPSTEALCNT , SSOLDERRCNT, NOSPACEERRCNT, MAXQUERYLEN, TUNED_UNDORETENTION, TUNED_UNDORETENTION/60/60 hours from gv$undostat where begin_time between (sysdate-.16) and sysdate order by inst_id, begin_time / set termout on set trimout off set trimspool off ttitle off set pages 999 set lines 150 set verify off set termout off set trimout on set trimspool on REM REM ------------------------------------------------------------------------ col name format a30 col gets format 9,999,999 col waits format 9,999,999 PROMPT ROLLBACK HIT STATISTICS: REM REM GETS - # of gets on the rollback segment header REM WAITS - # of waits for the rollback segment header set head on; select name, waits, gets from v$rollstat, v$rollname where v$rollstat.usn = v$rollname.usn / col pct head "< 2% ideal" select 'The average of waits/gets is '|| round((sum(waits) / sum(gets)) * 100,2)||'%' PCT From v$rollstat / PROMPT REDO CONTENTION STATISTICS: REM REM If the ratio of waits to gets is more than 1% or 2%, consider REM creating more rollback segments REM REM Another way to gauge rollback contention is: REM column xn1 format 9999999 column xv1 new_value xxv1 noprint select class, count from v$waitstat where class in ('system undo header', 'system undo block', 'undo header', 'undo block' ) / set head off select 'Total requests = '||sum(count) xn1, sum(count) xv1 from v$waitstat / select 'Contention for system undo header = '|| (round(count/(&xxv1+0.00000000001),4)) * 100||'%' from v$waitstat where class = 'system undo header' / select 'Contention for system undo block = '|| (round(count/(&xxv1+0.00000000001),4)) * 100||'%' from v$waitstat where class = 'system undo block' / select 'Contention for undo header = '|| (round(count/(&xxv1+0.00000000001),4)) * 100||'%' from v$waitstat where class = 'undo header' / select 'Contention for undo block = '|| (round(count/(&xxv1+0.00000000001),4)) * 100||'%' from v$waitstat where class = 'undo block' / REM REM NOTE: Not as useful with AUM configured REM REM If the percentage for an area is more than 1% or 2%, consider REM creating more rollback segments. Note: This value is usually very REM small REM and has been rounded to 4 places. REM REM ------------------------------------------------------------------------ REM REM The following shows how often user processes had to wait for space in REM the redo log buffer: select name||' = '||value from v$sysstat where name = 'redo log space requests' / REM REM This value should be near 0. If this value increments consistently, REM processes have had to wait for space in the redo buffer. If this REM condition exists over time, increase the size of LOG_BUFFER in the REM init.ora file in increments of 5% until the value nears 0. REM ** NOTE: increasing the LOG_BUFFER value will increase total SGA size. REM REM ----------------------------------------------------------------------- col name format a15 col gets format 9999999 col misses format 9999999 col immediate_gets heading 'IMMED GETS' format 9999999 col immediate_misses heading 'IMMED MISS' format 9999999 col sleeps format 999999 PROMPT LATCH CONTENTION: REM REM GETS - # of successful willing-to-wait requests for a latch REM MISSES - # of times an initial willing-to-wait request was unsuccessful REM IMMEDIATE_GETS - # of successful immediate requests for each latch REM IMMEDIATE_MISSES = # of unsuccessful immediate requests for each latch REM SLEEPS - # of times a process waited and requests a latch after an REM initial willing-to-wait request REM REM If the latch requested with a willing-to-wait request is not REM available, the requesting process waits a short time and requests REM again. REM If the latch requested with an immediate request is not available, REM the requesting process does not wait, but continues processing REM set head on select name, gets, misses, immediate_gets, immediate_misses, sleeps from v$latch where name in ('redo allocation', 'redo copy') / set head off select 'Ratio of MISSES to GETS: '|| round((sum(misses)/(sum(gets)+0.00000000001) * 100),2)||'%' from v$latch where name in ('redo allocation', 'redo copy') / select 'Ratio of IMMEDIATE_MISSES to IMMEDIATE_GETS: '|| round((sum(immediate_misses)/ (sum(immediate_misses+immediate_gets)+0.00000000001) * 100),2)||'%' from v$latch where name in ('redo allocation', 'redo copy') / set head on REM REM If either ratio exceeds 1%, performance will be affected. REM REM Decreasing the size of LOG_SMALL_ENTRY_MAX_SIZE reduces the number of REM processes copying information on the redo allocation latch. REM REM Increasing the size of LOG_SIMULTANEOUS_COPIES will reduce contention REM for redo copy latches. REM REM ----------------------------------------------------------------- REM This looks at overall i/o activity against individual REM files within a tablespace REM REM Look for a mismatch across disk drives in terms of I/O REM REM Also, examine the Blocks per Read Ratio for heavily accessed REM TSs - if this value is significantly above 1 then you may have REM full tablescans occurring (with multi-block I/O) REM REM If activity on the files is unbalanced, move files around to balance REM the load. Should see an approximately even set of numbers across files REM set space 1 PROMPT REPORTING I/O STATISTICS: column pbr format 99999999 heading 'Physical|Blk Read' column pbw format 999999 heading 'Physical|Blks Wrtn' column pyr format 999999 heading 'Physical|Reads' column readtim format 99999999 heading 'Read|Time' column name format a55 heading 'DataFile Name' column writetim format 99999999 heading 'Write|Time' compute sum of f.phyblkrd, f.phyblkwrt on report select fs.name name, f.phyblkrd pbr, f.phyblkwrt pbw, f.readtim, f.writetim from v$filestat f, v$datafile fs where f.file# = fs.file# order by fs.name / REM REM ----------------------------------------------------------------- PROMPT GENERATING WAIT STATISTICS: REM REM This will show wait stats for certain kernel instances. This REM may show the need for additional rbs, wait lists, db_buffers REM column class heading 'Class Type' column count heading 'Times Waited' format 99,999,999 column time heading 'Total Times' format 99,999,999 select class, count, time from v$waitstat where count > 0 order by class / REM REM Look at the wait statistics generated above (if any). They will REM tell you where there is contention in the system. There will REM usually be some contention in any system - but if the ratio of REM waits for a particular operation starts to rise, you may need to REM add additional resource, such as more database buffers, log buffers, REM or rollback segments REM REM ----------------------------------------------------------------- PROMPT ROLLBACK EXTENT STATISTICS: REM column usn format 999 heading 'Undo #' column extents format 999 heading 'Extents' column rssize format 999,999,999 heading 'Size in|Bytes' column optsize format 999,999,999 heading 'Optimal|Size' column hwmsize format 99,999,999 heading 'High Water|Mark' column shrinks format 9,999 heading 'Num of|Shrinks' column wraps format 9,999 heading 'Num of|Wraps' column extends format 999,999 heading 'Num of|Extends' column aveactive format 999,999,999 heading 'Average size|Active Extents' column rownum noprint select usn, extents, rssize, optsize, hwmsize, shrinks, wraps, extends, aveactive from v$rollstat order by rownum / set termout on set trimout off set trimspool off set lines 120 set pages 999 set termout off set trimout on set trimspool on prompt prompt ############## RUNTIME ############## prompt col rdate head "Run Time" select sysdate rdate from dual; prompt prompt ############## HISTORICAL DATA ############## prompt col x format 999,999 head "Max Concurrent|Last 7 Days" col y format 999,999 head "Max Concurrent|Since Startup" select max(maxconcurrency) x from v$undostat / select max(maxconcurrency) y from sys.wrh$_undostat / col i format 999,999 head "1555 Errors" col j format 999,999 head "Undo Space Errors" select sum(ssolderrcnt) i from v$undostat where end_time > sysdate-2 / select sum(nospaceerrcnt) j from v$undostat where end_time > sysdate-2 / prompt prompt ############## CURRENT STATUS OF SEGMENTS ############## prompt ############## SNAPSHOT IN TIME INFO ############## prompt ##############(SHOWS CURRENT UNDO ACTIVITY)############## prompt col segment_name format a30 head "Segment Name" col "ACT BYTES" format 999,999,999,999 head "Active Bytes" col "UNEXP BYTES" format 999,999,999,999 head "Unexpired Bytes" col "EXP BYTES" format 999,999,999,999 head "Expired Bytes" select segment_name, nvl(sum(act),0) "ACT BYTES", nvl(sum(unexp),0) "UNEXP BYTES", nvl(sum(exp),0) "EXP BYTES" from (select segment_name, nvl(sum(bytes),0) act,00 unexp, 00 exp from dba_undo_extents where status='ACTIVE' group by segment_name union select segment_name, 00 act, nvl(sum(bytes),0) unexp, 00 exp from dba_undo_extents where status='UNEXPIRED' group by segment_name union select segment_name, 00 act, 00 unexp, nvl(sum(bytes),0) exp from dba_undo_extents where status='EXPIRED' group by segment_name) group by segment_name order by 1 / prompt prompt ############## UNDO SPACE USAGE ############## prompt col usn format 999,999 head "Segment#" col shrinks format 999,999,999 head "Shrinks" col aveshrink format 999,999,999 head "Avg Shrink Size" select usn, shrinks, aveshrink from v$rollstat / set termout on set trimout off set trimspool off set pages 999 set termout off set trimout on set trimspool on prompt prompt ############## RUNTIME ############## prompt col rdate head "Run Time" select sysdate rdate from dual; col inst_id format 999 head "Instance #" col Parameter format a35 wrap col "Session Value" format a25 wrapped col "Instance Value" format a25 wrapped prompt prompt ############## PARAMETERS ############## prompt select a.inst_id, a.ksppinm "Parameter", b.ksppstvl "Session Value", c.ksppstvl "Instance Value" from x$ksppi a, x$ksppcv b, x$ksppsv c where a.indx = b.indx and a.indx = c.indx and a.inst_id=b.inst_id and b.inst_id=c.inst_id and a.ksppinm in ('_undo_autotune', '_smu_debug_mode', '_highthreshold_undoretention', 'undo_tablespace','undo_retention','undo_management') order by 2; set termout on set trimout off set trimspool off set pages 999 set termout off set trimout on set trimspool on prompt prompt ############## RUNTIME ############## prompt col rdate head "Run Time" select sysdate rdate from dual; prompt prompt ############## WAITS FOR UNDO (Since Startup) ############## prompt col inst_id head "Instance#" col eq_type format a3 head "Enq" col total_req# format 999,999,999,999,999,999 head "Total Requests" col total_wait# format 999,999 head "Total Waits" col succ_req# format 999,999,999,999,999,999 head "Successes" col failed_req# format 999,999,999999 head "Failures" col cum_wait_time format 999,999,999 head "Cummalitve|Time" select * from v$enqueue_stat where eq_type='US' union select * from v$enqueue_stat where eq_type='HW' / prompt prompt ############## LOCKS FOR UNDO ############## prompt col addr head "ADDR" col KADDR head "KADDR" col sid head "Session" col osuser format a10 head "OS User" col machine format a15 head "Machine" col program format a17 head "Program" col process format a7 head "Process" col lmode head "Lmode" col request head "Request" col ctime format 9,999 head "Time|(Mins)" col block head "Blocking?" select /*+ RULE */ a.SID, b.process, b.OSUSER, b.MACHINE, b.PROGRAM, addr, kaddr, lmode, request, round(ctime/60/60,0) ctime, block from v$lock a, v$session b where a.sid=b.sid and a.type='US' / prompt prompt ############## TUNED RETENTION HISTORY (Last 2 Days) ############## prompt ############## LOWEST AND HIGHEST DATA ############## prompt col low format 999,999,999,999 head "Undo Retention|Lowest Tuned Value" col high format 999,999,999,999 head "Undo Retention|Highest Tuned Value" select end_time, tuned_undoretention from v$undostat where tuned_undoretention = ( select min(tuned_undoretention) low from v$undostat where end_time > sysdate-2) / select end_time, tuned_undoretention from v$undostat where tuned_undoretention = ( select max(tuned_undoretention) high from v$undostat where end_time > sysdate-2) / prompt prompt ############## CURRENT TRANSACTIONS ############## prompt col sql_text format a40 word_wrapped head "SQL Code" select a.start_date, a.start_scn, a.status, c.sql_text from v$transaction a, v$session b, v$sqlarea c where b.saddr=a.ses_addr and c.address=b.sql_address and b.sql_hash_value=c.hash_value / select current_scn from v$database / col a format 999,999 head "UnexStolen" col b format 999,999 head "ExStolen" col c format 999,999 head "UnexReuse" col d format 999,999 head "ExReuse" prompt prompt ############## WHO'S STEALING WHAT? (Last 2 Days) ############## prompt select unxpstealcnt a, expstealcnt b, unxpblkreucnt c, expblkreucnt d from v$undostat where (unxpstealcnt > 0 or expstealcnt > 0) and end_time > sysdate-2 / set termout on set trimout off set trimspool off set pages 999 set termout off set trimout on set trimspool on prompt prompt ############## RUNTIME ############## prompt col rdate head "Run Time" select sysdate rdate from dual; col current_scn head "SCN Now" col start_date head "Trans Started" col start_scn head "SCN for Trans" col ses_addr head "ADDR" prompt prompt ############## Historical V$UNDOSTAT (Last 2 Days) ############## prompt col end_time format a18 Head "Date/Time" col maxq format 999,999 head "Query|Maximum|Minutes" col maxquerysqlid head "SqlID" col undotsn format 999,999 head "TBS" col undoblks format 999,999,999 head "Undo|Blocks" col txncount format 999,999,999 head "# of|Trans" col unexpiredblks format 999,999,999 head "# of Unexpired" col expiredblks format 999,999,999 head "# of Expired" col tuned format 999,999 head "Tuned Retention|(Minutes)" select end_time, round(maxquerylen/60,0) maxq, maxquerysqlid, undotsn, undoblks, txncount, unexpiredblks, expiredblks, round(tuned_undoretention/60,0) Tuned from dba_hist_undostat where end_time > sysdate-2 order by 1 / prompt prompt ############## RECENT MISSES FOR UNDO (Last 2 Days) ############## prompt set lines 500 select * from v$undostat where maxquerylen > tuned_undoretention and end_time > sysdate-2 order by 2 / select * from sys.wrh$_undostat where maxquerylen > tuned_undoretention and end_time > sysdate-2 order by 2 / prompt prompt ############## AUTO-TUNING TUNE-DOWN DATA ############## prompt ############## ROLLBACK DATA (Since Startup) ############## prompt col name format a60 head "Name" col value format 999,999,999 head "Counters" select name, value from v$sysstat where name like '%down retention%' or name like 'une down%' or name like '%undo segment%' or name like '%rollback%' or name like '%undo record%' / prompt prompt ############## Long Running Query History ############## prompt col end_time head "Date" col maxquerysqlid head "SQL ID" col runawayquerysqlid format a15 head "Runaway SQL ID" col results format a35 word_wrapped head "Space Issues" col status head "Status" col newret head "Tuned Down|Retention" select end_time, maxquerysqlid, runawayquerysqlid, status, decode(status,1,'Slot Active',4,'Reached Best Retention',5,'Reached Best Retention', 8, 'Runaway Query',9,'Runaway Query-Active',10,'Space Pressure', 11,'Space Pressure Currently', 16, 'Tuned Down (to undo_retention) due to Space Pressure', 17,'Tuned Down (to undo_retention) due to Space Pressure-Active', 18, 'Tuning Down due to Runaway', 19, 'Tuning Down due to Runaway-Active', 28, 'Runaway tuned down to last tune down value', 29, 'Runaway tuned down to last tune down value', 32, 'Max Tuned Down - Not Auto-Tuning', 33, 'Max Tuned Down - Not Auto-Tuning (Active)', 37, 'Max Tuned Down - Not Auto-Tuning (Active)', 38, 'Max Tuned Down - Not Auto-Tuning', 39, 'Max Tuned Down - Not Auto-Tuning (Active)', 40, 'Max Tuned Down - Not Auto-Tuning', 41, 'Max Tuned Down - Not Auto-Tuning (Active)', 42, 'Max Tuned Down - Not Auto-Tuning', 44, 'Max Tuned Down - Not Auto-Tuning', 45, 'Max Tuned Down - Not Auto-Tuning (Active)', 'Other ('||status||')') Results, spcprs_retention NewRet from sys.wrh$_undostat where status > 1 / prompt prompt ############## Details on Long Run Queries ############## prompt col sql_fulltext head "SQL Text" Col sql_id heading "SQL ID" select sql_id, sql_fulltext, last_load_time "Last Load", round(elapsed_time/60/60/24,0) "Elapsed Days" from v$sql where sql_id in (select maxquerysqlid from sys.wrh$_undostat where status > 1) / set termout on set trimout off set trimspool off set pages 999 set termout off set trimout on set trimspool on prompt prompt ############## RUNTIME ############## prompt col rdate head "Run Time" select sysdate rdate from dual; prompt prompt ############## IN USE Undo Data ############## prompt select ((select (nvl(sum(bytes),0)) from dba_undo_extents where tablespace_name in (select tablespace_name from dba_tablespaces where retention like '%GUARANTEE' ) and status in ('ACTIVE','UNEXPIRED')) *100) / (select sum(bytes) from dba_data_files where tablespace_name in (select tablespace_name from dba_tablespaces where retention like '%GUARANTEE' )) "PCT_INUSE" from dual; select tablespace_name, extent_management, allocation_type, segment_space_management, retention from dba_tablespaces where retention like '%GUARANTEE' / col c format 999,999,999,999 head "Sum of Free" select (nvl(sum(bytes),0)) c from dba_free_space where tablespace_name in (select tablespace_name from dba_tablespaces where retention like '%GUARANTEE') / col d format 999,999,999,999 head "Total Bytes" select sum(bytes) d from dba_data_files where tablespace_name in (select tablespace_name from dba_tablespaces where retention like '%GUARANTEE') / PROMPT PROMPT ############## UNDO SEGMENTS ############## PROMPT col status head "Status" col z format 999,999 head "Total Extents" break on report compute sum on report of z select status, count(*) z from dba_undo_extents group by status / col z format 999,999 head "Undo Segments" select status, count(*) z from dba_rollback_segs group by status / prompt prompt ############## CURRENT STATUS OF SEGMENTS ############## prompt ############## SNAPSHOT IN TIME INFO ############## prompt ##############(SHOWS CURRENT UNDO ACTIVITY)############## prompt col segment_name format a30 head "Segment Name" col "ACT BYTES" format 999,999,999,999 head "Active Bytes" col "UNEXP BYTES" format 999,999,999,999 head "Unexpired Bytes" col "EXP BYTES" format 999,999,999,999 head "Expired Bytes" select segment_name, nvl(sum(act),0) "ACT BYTES", nvl(sum(unexp),0) "UNEXP BYTES", nvl(sum(exp),0) "EXP BYTES" from (select segment_name, nvl(sum(bytes),0) act,00 unexp, 00 exp from dba_undo_extents where status='ACTIVE' group by segment_name union select segment_name, 00 act, nvl(sum(bytes),0) unexp, 00 exp from dba_undo_extents where status='UNEXPIRED' group by segment_name union select segment_name, 00 act, 00 unexp, nvl(sum(bytes),0) exp from dba_undo_extents where status='EXPIRED' group by segment_name) group by segment_name order by 1 / prompt prompt ############## UNDO SPACE USAGE ############## prompt col usn format 999,999 head "Segment#" col shrinks format 999,999,999 head "Shrinks" col aveshrink format 999,999,999 head "Avg Shrink Size" select usn, shrinks, aveshrink from v$rollstat / set termout on set trimout off set trimspool off spool off
转自：http://www.cnblogs.com/macleanoracle/archive/2010/06/03/2967435.html