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Oracle 、Oceanbase、GoldenDB数据库比较系列(二十五)：sql profile/ outline 影响范围（中）

在ORACLE中，SQL Profile 是对 SQL 语句文本的数据库级匹配。由于相同的 SQL 文本在不同用户下可能会受到影响，因此需要一些方法来避免这种情况。OceanBase 提供了 outline 功能，可以用于固定执行计划。那么在 OceanBase 中是否存在与 ORACLE 类似的、影响不同用户的问题呢？多个用户的相同 SQL 语句和相同的表是否共享同一个 outline 呢？outline 是全库共享的还是用户级私有的？

Oracle 、Oceanbase、GoldenDB数据库比较系列(二十四)：sql profile/ outline 影响范围（上）
Oracle 、Oceanbase、GoldenDB数据库比较系列(二十五)：sql profile/ outline 影响范围（中）

–测试Oceanbase V4.2.1 for oracle租户

初始化数据
--首先同一个租户创建两个用户anbob, weejar，省略

obclient [SYS]> grant dba to weejar,anbob;
Query OK, 0 rows affected (1.183 sec)

SQL> create table weejar.test_profile(id int,name varchar2(100));
Table created.

SQL> create table anbob.test_profile(id int,name varchar2(100));
Table created.

obclient [SYS]> insert into anbob.test_profile select 1,'weejar'||rownum from dual connect by rownum<=10000; 
Query OK, 10000 rows affected (2.516 sec) 
Records: 10000 Duplicates: 0 Warnings: 0 

obclient [SYS]> insert into weejar.test_profile select rownum,'weejar'||rownum from xmltable('1 to 10000');
ORA-00600: internal error code, arguments: -5055, FUNCTION XMLTABLE does not exist     --- No supported XMLTABLE

obclient [SYS]> insert into weejar.test_profile select rownum,'weejar'||rownum from dual connect by rownum<=10000;
 Query OK, 10000 rows affected (1.950 sec) 
Records: 10000 Duplicates: 0 Warnings: 0 

obclient [SYS]> create index anbob.idx_test_profile on anbob.test_profile(id);
Query OK, 0 rows affected (28.000 sec)

obclient [SYS]>  create index weejar.idx_test_profile on weejar.test_profile(id);
Query OK, 0 rows affected (31.503 sec)

Note:
和上篇测试一样，两个用户，分别创建一个相同的表，数据不同的选择率，用于full table scan 和index scan。

验证执行计划

--- # weejar user

[root@localhost 4.2.3]# obclient -h192.168.56.100 -P2883 -uweejar@ob_ora -pweejar
Welcome to the OceanBase.  Commands end with ; or \g.
Your OceanBase connection id is 524289
Server version: OceanBase 4.2.1.2 (r102010012023120119-130bf91ba413a00bb696fe8853906fde1f29f83d) (Built Dec  1 2023 20:00:25)
Copyright (c) 2000, 2018, OceanBase and/or its affiliates. All rights reserved.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

obclient [WEEJAR]> explain select * from test_profile where id=1;
+-----------------------------------------------------------------------------------------------------+
| Query Plan                                                                                          |
+-----------------------------------------------------------------------------------------------------+
| ==========================================================================                          |
| |ID|OPERATOR        |NAME                          |EST.ROWS|EST.TIME(us)|                          |
| --------------------------------------------------------------------------                          |
| |0 |TABLE RANGE SCAN|TEST_PROFILE(IDX_TEST_PROFILE)|1       |7           |                          |
| ==========================================================================                          |
| Outputs & filters:                                                                                  |
| -------------------------------------                                                               |
|   0 - output([TEST_PROFILE.ID], [TEST_PROFILE.NAME]), filter(nil), rowset=16                        |
|       access([TEST_PROFILE.__pk_increment], [TEST_PROFILE.ID], [TEST_PROFILE.NAME]), partitions(p0) |
|       is_index_back=true, is_global_index=false,                                                    |
|       range_key([TEST_PROFILE.ID], [TEST_PROFILE.__pk_increment]), range(1,MIN ; 1,MAX),            |
|       range_cond([TEST_PROFILE.ID = 1])                                                             |
+-----------------------------------------------------------------------------------------------------+
12 rows in set (0.485 sec)

--- # anbob user

# obclient -h192.168.56.100 -P2883 -uanbob@ob_ora -panbob
Welcome to the OceanBase.  Commands end with ; or \g.
Your OceanBase connection id is 6
Server version: OceanBase 4.2.1.2 (r102010012023120119-130bf91ba413a00bb696fe8853906fde1f29f83d) (Built Dec  1 2023 20:00:25)

Copyright (c) 2000, 2018, OceanBase and/or its affiliates. All rights reserved.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

obclient [ANBOB]> explain select * from test_profile where id=1;
+-------------------------------------------------------------------------------------------------+
| Query Plan                                                                                      |
+-------------------------------------------------------------------------------------------------+
| =======================================================                                         |
| |ID|OPERATOR       |NAME        |EST.ROWS|EST.TIME(us)|                                         |
| -------------------------------------------------------                                         |
| |0 |TABLE FULL SCAN|TEST_PROFILE|10000   |420         |                                         |
| =======================================================                                         |
| Outputs & filters:                                                                              |
| -------------------------------------                                                           |
|   0 - output([TEST_PROFILE.ID], [TEST_PROFILE.NAME]), filter([TEST_PROFILE.ID = 1]), rowset=256 |
|       access([TEST_PROFILE.ID], [TEST_PROFILE.NAME]), partitions(p0)                            |
|       is_index_back=false, is_global_index=false, filter_before_indexback[false],               |
|       range_key([TEST_PROFILE.__pk_increment]), range(MIN ; MAX)always true                     |
+-------------------------------------------------------------------------------------------------+
11 rows in set (0.346 sec)


不用户相同SQL不同的表，OUTLINE共享？
在Oceanbase中创建 Outline，可以通过两种方式创建，一种是通过 SQL_TEXT（用户执行的带参数的原始语句），另一种是通过 SQL_ID 创建。 注：创建 Outline 需要进入对应的数据库下执行。，当 SQL_ID 相同时，使用 SQL_TEXT 方式创建的 Outline 会覆盖 SQL_ID 方式创建的 Outline，SQL_TEXT 方式创建的优先级更高。

# anbob
obclient [ANBOB]> select /*anbob_test*/ * from test_profile where id=1;
+------+-------------+
| ID   | NAME        |
+------+-------------+
|    1 | weejar1     |
|    1 | weejar2     |
|    1 | weejar3     |
...
+------+-------------+
10000 rows in set (0.264 sec)


#weejar
obclient [WEEJAR]> select /*anbob_test*/ * from test_profile where id=1;
+------+---------+
| ID   | NAME    |
+------+---------+
|    1 | weejar1 |
+------+---------+
1 row in set (0.562 sec)

# SYS
select tenant_id,db_id,svr_ip,svr_port,plan_id,sql_id,query_sql from GV$OB_PLAN_CACHE_PLAN_STAT where lower(query_sql) not like '%plan_cache_plan_stat%' and query_sql like '%anbob_test%';

obclient [SYS]> select tenant_id,db_id,svr_ip,svr_port,plan_id,sql_id,query_sql,SCHEMA_VERSION,EXECUTIONS,ROWS_PROCESSED,LARGE_QUERYS,OUTLINE_VERSION,OUTLINE_ID,HINTS_INFO from GV$OB_PLAN_CACHE_PLAN_STAT where lower(query_sql) not like '%plan_cache_plan_stat%' and query_sql like '%anbob_test%' \G
*************************** 1. row ***************************
      TENANT_ID: 1002
          DB_ID: 500003
         SVR_IP: 192.168.56.100
       SVR_PORT: 2882
        PLAN_ID: 128
         SQL_ID: 799B8543872CDA344B34E9BF5E0107E9
      QUERY_SQL: select /*anbob_test*/ * from test_profile where id=1
 SCHEMA_VERSION: 1721902231508616
     EXECUTIONS: 1
 ROWS_PROCESSED: 10000
   LARGE_QUERYS: 0
OUTLINE_VERSION: 0
     OUTLINE_ID: -1
     HINTS_INFO: NULL
*************************** 2. row ***************************
      TENANT_ID: 1002
          DB_ID: 500005
         SVR_IP: 192.168.56.100
       SVR_PORT: 2882
        PLAN_ID: 129
         SQL_ID: 799B8543872CDA344B34E9BF5E0107E9
      QUERY_SQL: select /*anbob_test*/ * from test_profile where id=1
 SCHEMA_VERSION: 1721902231508616
     EXECUTIONS: 1
 ROWS_PROCESSED: 1
   LARGE_QUERYS: 0
OUTLINE_VERSION: 0
     OUTLINE_ID: -1
     HINTS_INFO: NULL
2 rows in set (0.034 sec)

obclient [WEEJAR]> select PLAN_DEPTH,PLAN_LINE_ID,OPERATOR,NAME from gv$ob_plan_cache_plan_explain;
Empty set (0.093 sec)

obclient [SYS]> select SQL_ID,PLAN_HASH,PLAN_ID,PARENT_ID,DEPTH,OPERATOR,OBJECT_OWNER,OBJECT_NAME,OBJECT_ALIAS from V$OB_SQL_PLAN where plan_id=128;
+----------------------------------+----------------------+---------+-----------+-------+-----------------+--------------+--------------+--------------+
| SQL_ID                           | PLAN_HASH            | PLAN_ID | PARENT_ID | DEPTH | OPERATOR        | OBJECT_OWNER | OBJECT_NAME  | OBJECT_ALIAS |
+----------------------------------+----------------------+---------+-----------+-------+-----------------+--------------+--------------+--------------+
| 799B8543872CDA344B34E9BF5E0107E9 | 15601764933452318478 |     128 |        -1 |     0 | TABLE FULL SCAN | ANBOB        | TEST_PROFILE | TEST_PROFILE |
+----------------------------------+----------------------+---------+-----------+-------+-----------------+--------------+--------------+--------------+
1 row in set (0.081 sec)

obclient [SYS]> select SQL_ID,PLAN_HASH,PLAN_ID,PARENT_ID,DEPTH,OPERATOR,OBJECT_OWNER,OBJECT_NAME,OBJECT_ALIAS from V$OB_SQL_PLAN where plan_id=129;
+----------------------------------+---------------------+---------+-----------+-------+------------------+--------------+--------------+--------------------------------+
| SQL_ID                           | PLAN_HASH           | PLAN_ID | PARENT_ID | DEPTH | OPERATOR         | OBJECT_OWNER | OBJECT_NAME  | OBJECT_ALIAS                   |
+----------------------------------+---------------------+---------+-----------+-------+------------------+--------------+--------------+--------------------------------+
| 799B8543872CDA344B34E9BF5E0107E9 | 1212772377093033590 |     129 |        -1 |     0 | TABLE RANGE SCAN | WEEJAR       | TEST_PROFILE | TEST_PROFILE(IDX_TEST_PROFILE) |
+----------------------------------+---------------------+---------+-----------+-------+------------------+--------------+--------------+--------------------------------+
1 row in set (0.105 sec)

# weejar 
obclient [WEEJAR]> create or replace outline outl_799B8543872CDA344B34E9BF5E0107E9 on '799B8543872CDA344B34E9BF5E0107E9' using hint /*+index(TEST_PROFILE IDX_TEST_PROFILE) */;
Query OK, 0 rows affected (2.677 sec)

# weejar
obclient [WEEJAR]> select /*anbob_test*/ * from test_profile where id=1;
+------+---------+
| ID   | NAME    |
+------+---------+
|    1 | weejar1 |
+------+---------+
1 row in set (0.101 sec)

# anbob
obclient [ANBOB]> select /*anbob_test*/ * from test_profile where id=1;
+------+-------------+
| ID   | NAME        |
+------+-------------+
|    1 | weejar1     |
|    1 | weejar2     |
|    1 | weejar3     |
...

# SYS
obclient [SYS]> select tenant_id,db_id,svr_ip,svr_port,plan_id,sql_id,query_sql,SCHEMA_VERSION,EXECUTIONS,ROWS_PROCESSED,LARGE_QUERYS,OUTLINE_VERSION,OUTLINE_ID,HINTS_INFO from GV$OB_PLAN_CACHE_PLAN_STAT where lower(query_sql) not like '%plan_cache_plan_stat%' and query_sql like '%anbob_test%' \G
*************************** 1. row ***************************
      TENANT_ID: 1002
          DB_ID: 500003
         SVR_IP: 192.168.56.100
       SVR_PORT: 2882
        PLAN_ID: 128
         SQL_ID: 799B8543872CDA344B34E9BF5E0107E9
      QUERY_SQL: select /*anbob_test*/ * from test_profile where id=1
 SCHEMA_VERSION: 1721902231508616
     EXECUTIONS: 2
 ROWS_PROCESSED: 20000
   LARGE_QUERYS: 0
OUTLINE_VERSION: 0
     OUTLINE_ID: -1
     HINTS_INFO: NULL
*************************** 2. row ***************************
      TENANT_ID: 1002
          DB_ID: 500005
         SVR_IP: 192.168.56.100
       SVR_PORT: 2882
        PLAN_ID: 164
         SQL_ID: 799B8543872CDA344B34E9BF5E0107E9
      QUERY_SQL: select /*anbob_test*/ * from test_profile where id=1
 SCHEMA_VERSION: 1722761417822032
     EXECUTIONS: 1
 ROWS_PROCESSED: 1
   LARGE_QUERYS: 0
OUTLINE_VERSION: 1722761417482704
     OUTLINE_ID: 500010
     HINTS_INFO: NULL
2 rows in set (0.106 sec)

obclient [SYS]> select * from dict where table_name like '%OUTLINE%';
+-----------------------------------+----------+
| TABLE_NAME                        | COMMENTS |
+-----------------------------------+----------+
| DBA_OB_OUTLINE_CONCURRENT_HISTORY | NULL     |
| DBA_OB_OUTLINES                   | NULL     |
+-----------------------------------+----------+
2 rows in set (0.058 sec)

obclient [SYS]> SELECT * FROM DBA_OB_OUTLINES \G
*************************** 1. row ***************************
      CREATE_TIME: 04-AUG-24 04.50.17.490412 PM
      MODIFY_TIME: 04-AUG-24 04.50.17.490412 PM
        TENANT_ID: 1002
      DATABASE_ID: 500005
       OUTLINE_ID: 500010
    DATABASE_NAME: WEEJAR
     OUTLINE_NAME: OUTL_799B8543872CDA344B34E9BF5E0107E9
VISIBLE_SIGNATURE:
         SQL_TEXT:
   OUTLINE_TARGET:
      OUTLINE_SQL:
           SQL_ID: 799B8543872CDA344B34E9BF5E0107E9
  OUTLINE_CONTENT: /*+index(TEST_PROFILE IDX_TEST_PROFILE) */

Note:
该视图从 V4.0.0 版本开始视图名由 GV$PLAN_CACHE_PLAN_STAT 调整为 GV$OB_PLAN_CACHE_PLAN_STAT。 GV$PLAN_CACHE_PLAN_EXPLAIN 调整为 GV$OB_PLAN_CACHE_PLAN_EXPLAIN.
在FOR oracle租户中，虽然Oceanbase也可以像oracle中1个数据库对应多个schema（user），但是低层仍旧是MySQL式的模式，schema就是database. 所以weejar 用户创建的outline属于WEEJAR database，未影响anbob 用户。  如果是2个用户查询相同用户的表呢？ outline会不会共享？

不用户相同SQL相同的表，OUTLINE共享？

# weejar
select /*anbob_full*/ * from weejar.test_profile where id=1;

# anbob
select /*anbob_full*/ * from weejar.test_profile where id=1;

# sys
 obclient [SYS]>  select tenant_id,db_id,svr_ip,svr_port,plan_id,sql_id,query_sql,SCHEMA_VERSION,EXECUTIONS,ROWS_PROCESSED,LARGE_QUERYS,OUTLINE_VERSION,OUTLINE_ID,HINTS_INFO from GV$OB_PLAN_CACHE_PLAN_STAT where lower(query_sql) not like '%plan_cache_plan_stat%' and query_sql like '%anbob_full%' \G
*************************** 1. row ***************************
      TENANT_ID: 1002
          DB_ID: 500003
         SVR_IP: 192.168.56.100
       SVR_PORT: 2882
        PLAN_ID: 176
         SQL_ID: 6DAA6297703A54EC92D35E71924B9E51
      QUERY_SQL: select /*anbob_full*/ * from weejar.test_profile where id=1
 SCHEMA_VERSION: 1722761417822032
     EXECUTIONS: 1
 ROWS_PROCESSED: 1
   LARGE_QUERYS: 0
OUTLINE_VERSION: 0
     OUTLINE_ID: -1
     HINTS_INFO: NULL
*************************** 2. row ***************************
      TENANT_ID: 1002
          DB_ID: 500005
         SVR_IP: 192.168.56.100
       SVR_PORT: 2882
        PLAN_ID: 177
         SQL_ID: 6DAA6297703A54EC92D35E71924B9E51
      QUERY_SQL: select /*anbob_full*/ * from weejar.test_profile where id=1
 SCHEMA_VERSION: 1722761417822032
     EXECUTIONS: 1
 ROWS_PROCESSED: 1
   LARGE_QUERYS: 0
OUTLINE_VERSION: 0
     OUTLINE_ID: -1
     HINTS_INFO: NULL
2 rows in set (0.151 sec)

 obclient [WEEJAR]>  select SQL_ID,PLAN_HASH,PLAN_ID,PARENT_ID,DEPTH,OPERATOR,OBJECT_OWNER,OBJECT_NAME,OBJECT_ALIAS from V$OB_SQL_PLAN where plan_id=176;
+----------------------------------+---------------------+---------+-----------+-------+------------------+--------------+--------------+--------------------------------+
| SQL_ID                           | PLAN_HASH           | PLAN_ID | PARENT_ID | DEPTH | OPERATOR         | OBJECT_OWNER | OBJECT_NAME  | OBJECT_ALIAS                   |
+----------------------------------+---------------------+---------+-----------+-------+------------------+--------------+--------------+--------------------------------+
| 6DAA6297703A54EC92D35E71924B9E51 | 1212772377093033590 |     176 |        -1 |     0 | TABLE RANGE SCAN | WEEJAR       | TEST_PROFILE | TEST_PROFILE(IDX_TEST_PROFILE) |
+----------------------------------+---------------------+---------+-----------+-------+------------------+--------------+--------------+--------------------------------+
1 row in set (0.100 sec)

obclient [WEEJAR]>  select SQL_ID,PLAN_HASH,PLAN_ID,PARENT_ID,DEPTH,OPERATOR,OBJECT_OWNER,OBJECT_NAME,OBJECT_ALIAS from V$OB_SQL_PLAN where plan_id=177;
+----------------------------------+---------------------+---------+-----------+-------+------------------+--------------+--------------+--------------------------------+
| SQL_ID                           | PLAN_HASH           | PLAN_ID | PARENT_ID | DEPTH | OPERATOR         | OBJECT_OWNER | OBJECT_NAME  | OBJECT_ALIAS                   |
+----------------------------------+---------------------+---------+-----------+-------+------------------+--------------+--------------+--------------------------------+
| 6DAA6297703A54EC92D35E71924B9E51 | 1212772377093033590 |     177 |        -1 |     0 | TABLE RANGE SCAN | WEEJAR       | TEST_PROFILE | TEST_PROFILE(IDX_TEST_PROFILE) |
+----------------------------------+---------------------+---------+-----------+-------+------------------+--------------+--------------+--------------------------------+
1 row in set (0.078 sec)

obclient [WEEJAR]> create or replace outline outl_6DAA6297703A54EC92D35E71924B9E51 on '6DAA6297703A54EC92D35E71924B9E51' using hint /*+FULL(TEST_PROFILE) */;
Query OK, 0 rows affected (0.146 sec)

# anbob
obclient [ANBOB]> select /*anbob_full*/ * from weejar.test_profile where id=1;
+------+---------+
| ID   | NAME    |
+------+---------+
|    1 | weejar1 |
+------+---------+
1 row in set (0.014 sec)
# weejar 
obclient [WEEJAR]> select /*anbob_full*/ * from weejar.test_profile where id=1;
+------+---------+
| ID   | NAME    |
+------+---------+
|    1 | weejar1 |
+------+---------+
1 row in set (0.336 sec)

obclient [WEEJAR]> select tenant_id,db_id,svr_ip,svr_port,plan_id,sql_id,query_sql,SCHEMA_VERSION,EXECUTIONS,ROWS_PROCESSED,LARGE_QUERYS,OUTLINE_VERSION,OUTLINE_ID,HINTS_INFO from GV$OB_PLAN_CACHE_PLAN_STAT where lower(query_sql) not like '%plan_cache_plan_stat%' and query_sql like '%anbob_full%' \G
*************************** 1. row ***************************
      TENANT_ID: 1002
          DB_ID: 500003
         SVR_IP: 192.168.56.100
       SVR_PORT: 2882
        PLAN_ID: 176
         SQL_ID: 6DAA6297703A54EC92D35E71924B9E51
      QUERY_SQL: select /*anbob_full*/ * from weejar.test_profile where id=1
 SCHEMA_VERSION: 1722761417822032
     EXECUTIONS: 1
 ROWS_PROCESSED: 1
   LARGE_QUERYS: 0
OUTLINE_VERSION: 0
     OUTLINE_ID: -1
     HINTS_INFO: NULL
*************************** 2. row ***************************
      TENANT_ID: 1002
          DB_ID: 500005
         SVR_IP: 192.168.56.100
       SVR_PORT: 2882
        PLAN_ID: 180
         SQL_ID: 6DAA6297703A54EC92D35E71924B9E51
      QUERY_SQL: select /*anbob_full*/ * from weejar.test_profile where id=1
 SCHEMA_VERSION: 1722762253742432
     EXECUTIONS: 1
 ROWS_PROCESSED: 1
   LARGE_QUERYS: 0
OUTLINE_VERSION: 1722762253741024
     OUTLINE_ID: 500011
     HINTS_INFO: NULL
2 rows in set (0.093 sec)

obclient [WEEJAR]> select SQL_ID,PLAN_HASH,PLAN_ID,PARENT_ID,DEPTH,OPERATOR,OBJECT_OWNER,OBJECT_NAME,OBJECT_ALIAS from V$OB_SQL_PLAN where plan_id=180;
+----------------------------------+----------------------+---------+-----------+-------+-----------------+--------------+--------------+--------------+
| SQL_ID                           | PLAN_HASH            | PLAN_ID | PARENT_ID | DEPTH | OPERATOR        | OBJECT_OWNER | OBJECT_NAME  | OBJECT_ALIAS |
+----------------------------------+----------------------+---------+-----------+-------+-----------------+--------------+--------------+--------------+
| 6DAA6297703A54EC92D35E71924B9E51 | 15601764933452318478 |     180 |        -1 |     0 | TABLE FULL SCAN | WEEJAR       | TEST_PROFILE | TEST_PROFILE |
+----------------------------------+----------------------+---------+-----------+-------+-----------------+--------------+--------------+--------------+
1 row in set (0.026 sec)

obclient [SYS]> SELECT * FROM DBA_OB_OUTLINES \G
*************************** 1. row ***************************
      CREATE_TIME: 04-AUG-24 04.50.17.490412 PM
      MODIFY_TIME: 04-AUG-24 04.50.17.490412 PM
        TENANT_ID: 1002
      DATABASE_ID: 500005
       OUTLINE_ID: 500010
    DATABASE_NAME: WEEJAR
     OUTLINE_NAME: OUTL_799B8543872CDA344B34E9BF5E0107E9
VISIBLE_SIGNATURE:
         SQL_TEXT:
   OUTLINE_TARGET:
      OUTLINE_SQL:
           SQL_ID: 799B8543872CDA344B34E9BF5E0107E9
  OUTLINE_CONTENT: /*+index(TEST_PROFILE IDX_TEST_PROFILE) */
*************************** 2. row ***************************
      CREATE_TIME: 04-AUG-24 05.04.13.710763 PM
      MODIFY_TIME: 04-AUG-24 05.04.13.710763 PM
        TENANT_ID: 1002
      DATABASE_ID: 500005
       OUTLINE_ID: 500011
    DATABASE_NAME: WEEJAR
     OUTLINE_NAME: OUTL_6DAA6297703A54EC92D35E71924B9E51
VISIBLE_SIGNATURE:
         SQL_TEXT:
   OUTLINE_TARGET:
      OUTLINE_SQL:
           SQL_ID: 6DAA6297703A54EC92D35E71924B9E51
  OUTLINE_CONTENT: /*+FULL(TEST_PROFILE) */
2 rows in set (0.064 sec)

Note:
相同表相同的SQL，只是SCHEMA_VERSION相同，但是一样不会共享outline.

小结:

在oceanbase中outline是用户私有的，不像oracle中的共享（默认）SQL PROFILE，这可能是基于不同的设计。只是默认情况，Oceanbase中这种减少了互相影响，也不用像oracle中配置session 变量再限制，这点考虑OB比Orale更佳。

  • 多个用户多个table(含索引)相同结构，对于相同的SQL文本，是否会互相影响？

不会！

  • 多个用户相同的table， 对于相同的SQL文本，是否会互相影响？

不会！

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