--制造数据
drop table test purge;
drop table test1 purge;
create table test as select * from dba_objects where rownum<10;
create table test1 as select * from dba_objects where rownum<10;
create index ind_t_object_id on test(object_id);
create index ind_t1_object_id on test1(object_id);
exec dbms_stats.gather_table_stats(user,'test',cascade => true);
exec dbms_stats.gather_table_stats(user,'test1',cascade => true);
--执行SQL
select /*+gg_test*/* from test t, test1 t1 where t.object_name like 'T%';
----------------------------------------------------------
Plan hash value: 702683263
------------------------------------------------------------------------------
| Id ?| Operation ? ? ? ? ? ?| Name ?| Rows ?| Bytes | Cost (%CPU)| Time ? ? |
------------------------------------------------------------------------------
| ? 0 | SELECT STATEMENT ? ? | ? ? ? | ? ? 9 | ?1350 | ? ? 6 ? (0)| 00:00:01 |
| ? 1 | ?MERGE JOIN CARTESIAN| ? ? ? | ? ? 9 | ?1350 | ? ? 6 ? (0)| 00:00:01 |
|* ?2 | ? TABLE ACCESS FULL ?| TEST ?| ? ? 1 | ? ?75 | ? ? 3 ? (0)| 00:00:01 |
| ? 3 | ? BUFFER SORT ? ? ? ?| ? ? ? | ? ? 9 | ? 675 | ? ? 3 ? (0)| 00:00:01 |
| ? 4 | ? ?TABLE ACCESS FULL | TEST1 | ? ? 9 | ? 675 | ? ? 3 ? (0)| 00:00:01 |
------------------------------------------------------------------------------
Predicate Information (identified by operation id):
---------------------------------------------------
? ?2 - filter("T"."OBJECT_NAME" LIKE 'T%')
统计信息
----------------------------------------------------------
? ? ? ? ? 1 ?recursive calls
? ? ? ? ? 0 ?db block gets
? ? ? ? ? 3 ?consistent gets
? ? ? ? ? 0 ?physical reads
? ? ? ? ? 0 ?redo size
? ? ? ?1991 ?bytes sent via SQL*Net to client
? ? ? ? 348 ?bytes received via SQL*Net from client
? ? ? ? ? 1 ?SQL*Net roundtrips to/from client
? ? ? ? ? 0 ?sorts (memory)
? ? ? ? ? 0 ?sorts (disk)
? ? ? ? ? 0 ?rows processed
(#keys=0) "T1"."OWNER"[VARCHAR2,30], "T1"."OBJECT_NAME"[VARCHAR2,128], "T1"."SUBOBJECT_NAME"[VARCHAR2,30], "T1"."OBJECT_ID"[NUMBER,22], "T1"."DATA_OBJECT_ID"[NUMBER,22], "T1"."OBJECT_TYPE"[VARCHAR2,19], "T1"."CREATED"[DATE,7], "T1"."LAST_DDL_TIME"[DATE,7], "T1"."TIMESTAMP"[VARCHAR2,19], "T1"."STATUS"[VARCHAR2,7], "T1"."TEMPORARY"[VARCHAR2,1], "T1"."GENERATED"[VARCHAR2,1], "T1"."SECONDARY"[VARCHAR2,1], "T1"."NAMESPACE"[NUMBER,22], "T1"."EDITION_NAME"[VARCHAR2,30]