目前，ob已经提供开发版供测试https://oceanbase.alipay.com/download，但只有mysql模式。
ob客户端可以从官方下载ODC、jdbc也可以从此下载，也就是IDE，oracle版本必须使用它连接。mysql版本可以使用navicat连接，为了体验一致的话，推荐用dbeaver。不过至今为止，navicat、sqlyog、mysql workbench都不支持自定义函数的只能提示，只支持内置函数。
oracle模式
1、支持自定义存储过程、函数
-- ob oracle版本函数 CREATE OR REPLACE FUNCTION demo_fun ( Name VARCHAR2 , vAge INTEGER , Sex VARCHAR2 DEFAULT '男' ) RETURN VARCHAR2 IS V_var VARCHAR2 ( 32 ) ; BEGIN V_var := name || '：' || TO_CHAR ( vAge ) || '岁，' || sex ; RETURN v_var ; END ; -- 不要加"/"结束符 select demo_fun('1',1) from dual; create or replace procedure procedure_name ( v_empno in varchar2, v_sal out number ) is vsal number(7,2); begin select 1 into vsal from dual; v_sal:=vsal; end; declare vsal number(7,2); begin procedure_name('7935',vsal); dbms_output.put_line(vsal); end;
2、支持自定义过程中执行动态SQL，如下：
create or replace procedure procedure_name ( v_empno in varchar2, v_sal out number ) is vsal number(7,2); begin execute immediate 'create table t1(id number primary key,nam varchar2(100))'; end; declare vsal number(7,2); begin procedure_name('7935',vsal); dbms_output.put_line(vsal); end;
-- 执行后会创建表t1
-- ob mysql版本
-- 否则创建存储过程、函数会报错。mysql/mariadb必须启用，OB不支持该参数 set global log_bin_trust_function_creators = on delimiter $$ CREATE FUNCTION StuNameById() RETURNS VARCHAR(45) RETURN 'stuname'; $$ delimiter ; select StuNameById()
-- ob mysql 创建存储过程 DELIMITER // CREATE PROCEDURE ShowStuScore() BEGIN SELECT '1' as name1,'2' as id; END // delimiter ; -- 但是ob mysql模式没有返回值，mysql/mariadb有返回值 call ShowStuScore()
3、支持自定义存储过程中执行ddl
-- ob mysql 创建存储过程 DELIMITER // CREATE PROCEDURE exec_ddl(S_NAME_IN CHAR(30)) BEGIN SET @SS = CONCAT('create table ',S_NAME_IN,'(id int primary key,nam varchar(100))'); PREPARE STMT FROM @SS; EXECUTE STMT; END // delimiter ; call exec_ddl('ob_t_2')
4、无论是oracle模式还是mysql模式，内部总归是基于mysql的，看系统参数就知道，show parameter报错，show variables like '%%'基本上是mysql参数，有一些ob、oracle的扩展参数，其中ob的很多抄了oracle隐含参数的特性，比如max_parallel_degree，完整的参数如下：
-- mysql模式
autocommit ON auto_increment_cache_size 1000000 auto_increment_increment 1 auto_increment_offset 1 binlog_row_image FULL block_encryption_mode aes-128-ecb character_set_client utf8mb4 character_set_connection utf8mb4 character_set_database utf8mb4 character_set_filesystem binary character_set_results utf8mb4 character_set_server utf8mb4 character_set_system utf8mb4 collation_connection utf8mb4_general_ci collation_database utf8mb4_general_ci collation_server utf8mb4_general_ci connect_timeout 10 datadir /usr/local/mysql/data/ div_precision_increment 4 error_on_overlap_time OFF explicit_defaults_for_timestamp ON foreign_key_checks OFF group_concat_max_len 1024 identity 0 init_connect interactive_timeout 28800 is_result_accurate ON last_insert_id 0 license lower_case_table_names 1 max_allowed_packet 4194304 max_sp_recursion_depth 0 max_user_connections 0 net_buffer_length 16384 net_read_timeout 30 net_write_timeout 60 ob_bnl_join_cache_size 10485760 ob_check_sys_variable ON ob_compatibility_mode MYSQL ob_create_table_strict_mode ON ob_default_replica_num 1 ob_early_lock_release OFF ob_enable_aggregation_pushdown ON ob_enable_blk_nestedloop_join OFF ob_enable_hash_group_by ON ob_enable_index_direct_select OFF ob_enable_jit OFF ob_enable_plan_cache ON ob_enable_sql_audit ON ob_enable_trace_log OFF ob_enable_transformation ON ob_enable_transmission_checksum ON ob_enable_truncate_flashback ON ob_interm_result_mem_limit 2147483648 ob_last_schema_version 1600655186941424 ob_log_level disabled ob_max_parallel_degree 32 ob_org_cluster_id 0 ob_plan_cache_evict_high_percentage 90 ob_plan_cache_evict_low_percentage 50 ob_plan_cache_percentage 5 ob_query_timeout 10000000 ob_read_consistency STRONG ob_reserved_meta_memory_percentage 10 ob_route_policy READONLY_ZONE_FIRST ob_sql_audit_percentage 3 ob_sql_work_area_percentage 5 ob_stmt_parallel_degree 1 ob_tcp_invited_nodes % ob_temp_tablespace_size_percentage 0 ob_timestamp_service GTS ob_trx_idle_timeout 120000000 ob_trx_timeout 100000000 optimizer_capture_sql_plan_baselines OFF optimizer_use_sql_plan_baselines OFF parallel_max_servers 10 parallel_servers_target 10 plugin_dir ./plugin_dir/ query_cache_size 1048576 query_cache_type OFF read_only OFF recyclebin ON sql_auto_is_null OFF sql_mode STRICT_ALL_TABLES sql_quote_show_create ON sql_select_limit 9223372036854775807 sql_throttle_cpu -1 sql_throttle_current_priority 100 sql_throttle_io -1 sql_throttle_logical_reads -1 sql_throttle_network -1 sql_throttle_priority -1 sql_throttle_rt -1 sql_warnings OFF system_time_zone +08:00 timestamp 0 time_zone +8:00 tracefile_identifier tx_isolation READ-COMMITTED tx_read_only OFF undo_retention 0 version 2.2.30 version_comment OceanBase 2.2.30 (r20200807074943-8db774b3cae3e41d7b06a2c9c82a2bee97eba0c0) (Built Aug 7 2020 08:06:34) wait_timeout 28800
下面是oracle模式：
oracle模式搞了一堆v$动态性能视图，v$parameter又没有，information_schema.session_variables也没有，就一不伦不类，关键两个模式无论数据字典、参数感觉都完全没有隔离，就一个试验品。
导出直接报错，真的是垃圾到家了。
5、执行计划和优化器提示
支持oracle模式的优化器提示，即使是在mysql模式。执行计划显示为oracle的执行计划，mysql虽然也是相同语法，但是执行计划出不来。如下：
这个odc是难用的不行了，ob也一样，不是KPI要求，我是不会用的。
看下obclient客户端工具：
[root@linux-dev ~]# rpm -ivh obclient-1.1.1-20190802211743.el7.alios7.x86_64.rpm 准备中... ################################# [100%] 正在升级/安装... 1:obclient-1.1.1-20190802211743.el7################################# [100%] [root@linux-dev ~]# obclient -h10.19.1.23 -P2883 -usys@oracle_tenant0_1#obtest -p123456 -c -A sys obclient: [Warning] Using a password on the command line interface can be insecure. Welcome to the OceanBase monitor. Commands end with ; or g. Your OceanBase connection id is 1652791 Server version: 5.6.25 OceanBase 2.2.30 (r20200807074943-8db774b3cae3e41d7b06a2c9c82a2bee97eba0c0) (Built Aug 7 2020 08:06:34) Copyright (c) 2000, 2018, Oracle and/or its affiliates. All rights reserved. Oracle is a registered trademark of Oracle Corporation and/or its affiliates. Other names may be trademarks of their respective owners. Type 'help;' or 'h' for help. Type 'c' to clear the current input statement. obclient> explain select * from ob_t_1 t,ob_t_2 t1 where t.id=t1.id -> ; ERROR-00942: table or view 'SYS.OB_T_1' does not exist obclient> explain select * from t,t1 where t.id=t1.id -> ; +------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+ | Query Plan | +------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+ | ====================================== |ID|OPERATOR |NAME|EST. ROWS|COST | -------------------------------------- |0 |HASH JOIN | |99000 |592998| |1 | TABLE SCAN|T |100000 |68478 | |2 | TABLE SCAN|T1 |100000 |61860 | ====================================== Outputs & filters: ------------------------------------- 0 - output([T.ID], [T.NAM], [T1.ID], [T1.NAM]), filter(nil), equal_conds([T.ID = T1.ID]), other_conds(nil) 1 - output([T.ID], [T.NAM]), filter(nil), access([T.ID], [T.NAM]), partitions(p0) 2 - output([T1.ID], [T1.NAM]), filter(nil), access([T1.ID], [T1.NAM]), partitions(p0) | +------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+ 1 row in set (0.00 sec) obclient> exit Bye [root@linux-dev ~]# ob obclient objcopy objdump [root@linux-dev ~]# obclient -h10.19.1.23 -P2883 -uroot@mysql_teant0_2#obtest -p123456 -c -A oceanbase obclient: [Warning] Using a password on the command line interface can be insecure. Welcome to the OceanBase monitor. Commands end with ; or g. Your OceanBase connection id is 1652810 Server version: 5.6.25/*这基本上就是基于mysql 5.6.25*/ OceanBase 2.2.30 (r20200807074943-8db774b3cae3e41d7b06a2c9c82a2bee97eba0c0) (Built Aug 7 2020 08:06:34) Copyright (c) 2000, 2018, Oracle and/or its affiliates. All rights reserved. Oracle is a registered trademark of Oracle Corporation and/or its affiliates. Other names may be trademarks of their respective owners. Type 'help;' or 'h' for help. Type 'c' to clear the current input statement. obclient> explain select * from ob_t_1 t,ob_t_2 t1 where t.id=t1.id; ERROR 1146 (42S02): Table 'oceanbase.ob_t_1' doesn't exist obclient> use test; Database changed obclient> explain select * from ob_t_1 t,ob_t_2 t1 where t.id=t1.id; +-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+ | Query Plan | +-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+ | ================================================================= |ID|OPERATOR |NAME |EST. ROWS|COST | ----------------------------------------------------------------- |0 |EXCHANGE IN DISTR | |100001 |402319| |1 | EXCHANGE OUT DISTR |:EX10001|100001 |274528| |2 | MERGE JOIN | |100001 |274528| |3 | EXCHANGE IN MERGE SORT DISTR | |100000 |125756| |4 | EXCHANGE OUT DISTR (BROADCAST)|:EX10000|100000 |61860 | |5 | TABLE SCAN |t |100000 |61860 | |6 | TABLE SCAN |t1 |100000 |61860 | ================================================================= Outputs & filters: ------------------------------------- 0 - output([t.id], [t.nam], [t1.id], [t1.nam]), filter(nil) 1 - output([t.id], [t.nam], [t1.id], [t1.nam]), filter(nil), dop=1 2 - output([t.id], [t.nam], [t1.id], [t1.nam]), filter(nil), equal_conds([t.id = t1.id]), other_conds(nil) 3 - output([t.id], [t.nam]), filter(nil), sort_keys([t.id, ASC]) 4 - output([t.id], [t.nam]), filter(nil), dop=1 5 - output([t.id], [t.nam]), filter(nil), access([t.id], [t.nam]), partitions(p0) 6 - output([t1.id], [t1.nam]), filter(nil), access([t1.id], [t1.nam]), partitions(p0) | +-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+ 1 row in set (0.01 sec)
也就oblient能用，问题是oracle、mysql执行计划还不通。也没官方文档说明执行计划的含义。
总体来说，非要用的话，推荐使用mysql模式。感觉oracle模式就是打补丁的。
ob初次学习可以参考https://blog.csdn.net/eo63y6pKI42Ilxr/article/details/82598438，符合实际，官网的资料全部不正确。
sql引起流程可以参考https://zhuanlan.zhihu.com/p/76950991，符合实际
ob高可用方案：https://oceanbase.alipay.com/community/articles/200123，其实引用到zk、kafka、redis集群、哨兵上是一个道理
ob的数据块组织方式：https://oceanbase.alipay.com/community/articles/200123