Oracle统计信息

小咪咪 2022-09-12 04:44 207阅读 0赞

## 统计信息 ##

show parameter statistics_level;

![在这里插入图片描述][6ab3f2b2c85a45f3aaaf46855ef63d36.png]

*  [STATISTICS\_LEVEL][STATISTICS_LEVEL]

## 表级别 ##

create tabel justForTest as select * from dba_users;
    exec dbms_stats.gather_table_stats('sys','justfortest');

![在这里插入图片描述][ba2632d8183d4dae960bcd75018b7d5c.png]  
![在这里插入图片描述][5b2502e4c09f426a9e83f9669679b0a9.png]

col owner format a10
    col table_name format a20
    col object_type format a20
    select owner, table_name, num_rows, object_type, last_analyzed from dba_tab_statistics where table_name=upper('justfortest');

![在这里插入图片描述][8b16b685dfee4dd2840ced58cf3ccc2b.png]

*  [DBA\_TAB\_STATISTICS][DBA_TAB_STATISTICS]
 *  [ALL\_TAB\_STATISTICS][ALL_TAB_STATISTICS]

## 数据库级别 ##

exec dbms_stats.gather_database_stats;

![在这里插入图片描述][78d55bd02d83405e9e4687bc6b5ec522.png]

*  [Oracle IO优化][Oracle IO]

[6ab3f2b2c85a45f3aaaf46855ef63d36.png]: /images/20220828/ffbac6882b874f3484c507b543da05b7.png
[STATISTICS_LEVEL]: https://docs.oracle.com/en/database/oracle/oracle-database/19/refrn/STATISTICS_LEVEL.html#GUID-16B23F95-8644-407A-A6C8-E85CADFA61FF
[ba2632d8183d4dae960bcd75018b7d5c.png]: /images/20220828/b4c68ae7d44341df977b0e5ac1feec56.png
[5b2502e4c09f426a9e83f9669679b0a9.png]: /images/20220828/2f8f3494504740cd8a474db21b82b7b9.png
[8b16b685dfee4dd2840ced58cf3ccc2b.png]: /images/20220828/fa05de8c1b784291b6fec3bd81534147.png
[DBA_TAB_STATISTICS]: https://docs.oracle.com/en/database/oracle/oracle-database/19/refrn/DBA_TAB_STATISTICS.html
[ALL_TAB_STATISTICS]: https://docs.oracle.com/en/database/oracle/oracle-database/19/refrn/ALL_TAB_STATISTICS.html
[78d55bd02d83405e9e4687bc6b5ec522.png]: /images/20220828/f1db10e969b846d983c468b5f5776671.png
[Oracle IO]: https://blog.csdn.net/webajax/article/details/38385513