DELETE PLAN_TABLE; EXPLAIN PLAN FOR SELECT * FROM t WHERE group2=1; SELECT * FROM TABLE(dbms_xplan.display());
Oracle utilities
The Oracle utility creating PLAN_TABLE:
D:\Oracle\product\11.2.0\dbhome_1\RDBMS\ADMIN\utlxplan.sql
The Oracle utility displays the last explain plan. It displays also parallel query information if the plan happens to run parallel:
D:\Oracle\product\11.2.0\dbhome_1\RDBMS\ADMIN\utlxplp.sql
The utility that does not displays parallel query information (sequential).
D:\Oracle\product\11.2.0\dbhome_1\RDBMS\ADMIN\utlxpls.sql
Hierarchical query
An example of use of hierarchical queries to print the last explain plan:
SELECT LPad(' ', level-1) || operation || ' (' || options || ')' AS operation, coalesce(object_name, ' ') object, cost, cardinality, bytes FROM plan_table START WITH id = 0 CONNECT BY PRIOR id=parent_id;
Example of the result:
OPERATION | OBJECT | COST | CARDINALITY | BYTES |
---|---|---|---|---|
SELECT STATEMENT () | 873 | 1000 | 20000 | |
TABLE ACCESS (BY INDEX ROWID) | T | 873 | 1000 | 20000 |
INDEX (RANGE SCAN) | T_GROUP2 | 5 | 1000 |