Statements that explicitly use subqueries against partition columns result in dynamic pruning. For example:
SQL> explain plan for select sum(amount_sold) from sales where time_id in (select time_id from times where fiscal_year = 2000); Explained. SQL> select * from table(dbms_xplan.display); PLAN_TABLE_OUTPUT PLAN_TABLE_OUTPUT ---------------------------------------------------------------------------------------------------- Plan hash value: 3827742054 ---------------------------------------------------------------------------------------------------- | Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time | Pstart| Pstop | ---------------------------------------------------------------------------------------------------- | 0 | SELECT STATEMENT | | 1 | 25 | 523 (5)| 00:00:07 | | | | 1 | SORT AGGREGATE | | 1 | 25 | | | | | |* 2 | HASH JOIN | | 191K| 4676K| 523 (5)| 00:00:07 | | | |* 3 | TABLE ACCESS FULL | TIMES | 304 | 3648 | 18 (0)| 00:00:01 | | | | 4 | PARTITION RANGE SUBQUERY| | 918K| 11M| 498 (4)| 00:00:06 |KEY(SQ)|KEY(SQ)| | 5 | TABLE ACCESS FULL | SALES | 918K| 11M| 498 (4)| 00:00:06 |KEY(SQ)|KEY(SQ)| ---------------------------------------------------------------------------------------------------- Predicate Information (identified by operation id): --------------------------------------------------- 2 - access("TIME_ID"="TIME_ID") 3 - filter("FISCAL_YEAR"=2000)
Oracle Database SQL Tuning Guide for more information about EXPLAIN PLAN
and how to interpret it