如何从PLAN_TABLEreturnhash_plan_value？

Question

我需要从 Oracle 中的查询计划自动获取 hash_plan_value。我知道当我执行 EXPLAIN PLAN for "My Query" 然后我可以看到它 SELECT PLAN_TABLE_OUTPUT FROM TABLE(DBMS_XPLAN.DISPLAY()) 向我展示了整个计划。

但我的观点是我没有在 PLAN_TABLE 的列中找到它。例如，我可以使用 SELECT COST,CARDINALITY, BYTES FROM PLAN_TABLE 获得 COST、CARDINALITY 和 BYTES 有没有办法获得 PLAN_HASH_VALUE？我的意思是因为它显示了它就在那里，但我不知道在哪里。我希望我已经足够清楚了..

Answer 1

计划哈希存储在 PLAN_TABLE 行之一的 OTHER_XML 列中。

示例计划

explain plan set statement_id = 'TEST3' for select * from dual connect by level <= 10;
select * from table(dbms_xplan.display);

Plan hash value: 2874664061

-------------------------------------------------------------------------------------
| Id  | Operation                    | Name | Rows  | Bytes | Cost (%CPU)| Time     |
-------------------------------------------------------------------------------------
|   0 | SELECT STATEMENT             |      |     1 |     2 |     2   (0)| 00:00:01 |
|*  1 |  CONNECT BY WITHOUT FILTERING|      |       |       |            |          |
|   2 |   TABLE ACCESS FULL          | DUAL |     1 |     2 |     2   (0)| 00:00:01 |
-------------------------------------------------------------------------------------

Predicate Information (identified by operation id):
---------------------------------------------------

   1 - filter(LEVEL<=10)

要提取的查询 PLAN_HASH

select extractValue(xmltype(other_xml), '/other_xml/info[@type="plan_hash"]') plan_hash
from plan_table
where other_xml is not null
    and statement_id = 'TEST3';

PLAN_HASH
---------
2874664061

如何从PLAN_TABLEreturnhash_plan_value？

How to return hash_plan_value from PLAN_TABLE?

oracle

sql-execution-plan