INDEX FAST FULL SCAN 也无法开并行

来源：互联网发布：剪辑音乐软件手机软件编辑：程序博客网时间：2024/06/04 19:39
SQL> drop table t1 purge ;表已删除。SQL> create table t1 as select * from dba_objects;表已创建。SQL> insert into t1 select * from t1;已创建72665行。SQL> /已创建145330行。SQL> commit;提交完成。SQL> create index t_idx2 on t1(owner,object_name,status) nologging;索引已创建。SQL> select owner,object_name from t1 a where status='INVALID';已选择16行。执行计划----------------------------------------------------------Plan hash value: 2575195509-------------------------------------------------------------------------------| Id  | Operation     | Name   | Rows  | Bytes | Cost (%CPU)| Time     |-------------------------------------------------------------------------------|   0 | SELECT STATEMENT     |      |   145K|  5411K|   412(1)| 00:00:05 ||*  1 |  INDEX FAST FULL SCAN| T_IDX2 |   145K|  5411K|   412(1)| 00:00:05 |-------------------------------------------------------------------------------Predicate Information (identified by operation id):---------------------------------------------------   1 - filter("STATUS"='INVALID')统计信息----------------------------------------------------------  1  recursive calls  0  db block gets       1938  consistent gets  0  physical reads  0  redo size744  bytes sent via SQL*Net to client426  bytes received via SQL*Net from client  3  SQL*Net roundtrips to/from client  0  sorts (memory)  0  sorts (disk) 16  rows processedSQL> SQL> select /*+ parallel(a 4)*/ owner,object_name from t1 a where status='INVALID';已选择16行。执行计划----------------------------------------------------------Plan hash value: 2494645258--------------------------------------------------------------------------------------------------------------| Id  | Operation     | Name| Rows| Bytes | Cost (%CPU)| Time|    TQ  |IN-OUT| PQ Distrib |--------------------------------------------------------------------------------------------------------------|   0 | SELECT STATEMENT     ||   145K|  5411K|   252   (1)| 00:00:04 | ||     ||   1 |  PX COORDINATOR      ||||     || ||     ||   2 |   PX SEND QC (RANDOM)| :TQ10000 |   145K|  5411K|   252   (1)| 00:00:04 |  Q1,00 | P->S | QC (RAND)  ||   3 |    PX BLOCK ITERATOR ||   145K|  5411K|   252   (1)| 00:00:04 |  Q1,00 | PCWC |     ||*  4 |     TABLE ACCESS FULL| T1|   145K|  5411K|   252   (1)| 00:00:04 |  Q1,00 | PCWP |     |--------------------------------------------------------------------------------------------------------------Predicate Information (identified by operation id):---------------------------------------------------   4 - filter("STATUS"='INVALID')统计信息---------------------------------------------------------- 12  recursive calls  0  db block gets       4256  consistent gets       4125  physical reads  0  redo size871  bytes sent via SQL*Net to client426  bytes received via SQL*Net from client  3  SQL*Net roundtrips to/from client  0  sorts (memory)  0  sorts (disk) 16  rows processedINDEX FAST FULL SCAN 多快读 也无法走并行
0 0