在PT寻求帮助。 附加psuedo查询.. 下面使用的3个表都有大量的记录 t2~1000万， t1~15百万， t3~800万 使用并行提示。但成本没有太大帮助。成本超过20万
(SELECT /*+ parallel (a,8) parallel (b,8)*/
DISTINCT B.ACCNT_NUM
FROM s1.t1 a, s2.t2 b
WHERE a.accnt_num = b.accnt_num
AND product_key IN (SELECT product_key FROM s3.t3 WHERE prod_type_cd = 'S')
AND a.active_flg = 'Y'
AND a.deleted_flg = 'N'
GROUP BY B.ACCNT_NUM, a.product_key
HAVING COUNT (*) > 1)
安排：
| 0 | SELECT STATEMENT
| 1 | 54 | 204K (1)| 00:47:39 | | | | | | | 1 | PX COORDINATOR | | | | | | | | | | |
| 2 | PX SEND QC (RANDOM) | :TQ10004 | 1 | 54 | 204K (1)| 00:47:39 | | | Q1,04 | P->S | QC (RAND) |
| 3 | HASH UNIQUE | | 1 | 54 | 204K (1)| 00:47:39 | | | Q1,04 | PCWP | |
| 4 | PX RECEIVE | | 1 | 54 | 204K (1)| 00:47:39 | | | Q1,04 | PCWP | |
| 5 | PX SEND HASH | :TQ10003 | 1 | 54 | 204K (1)| 00:47:39 | | | Q1,03 | P->P | HASH |
|* 6 | FILTER | | | | | | | | Q1,03 | PCWC | |
| 7 | HASH GROUP BY | | 1 | 54 | 204K (1)| 00:47:39 | | | Q1,03 | PCWP | |
| 8 | PX RECEIVE | | 1 | 54 | 204K (1)| 00:47:39 | | | Q1,03 | PCWP | |
| 9 | PX SEND HASH | :TQ10002 | 1 | 54 | 204K (1)| 00:47:39 | | | Q1,02 | P->P | HASH |
| 10 | HASH GROUP BY | | 1 | 54 | 204K (1)| 00:47:39 | | | Q1,02 | PCWP | |
|* 11 | HASH JOIN | | 90476 | 4771K| 204K (1)| 00:47:39 | | | Q1,02 | PCWP | |
| 12 | PX RECEIVE | | 22572 | 462K| 66147 (1)| 00:15:27 | | | Q1,02 | PCWP | |
| 13 | PX SEND BROADCAST | :TQ10001 | 22572 | 462K| 66147 (1)| 00:15:27 | | | Q1,01 | P->P | BROADCAST |
|* 14 | TABLE ACCESS BY LOCAL INDEX ROWID| table 1 | 22572 | 462K| 66147 (1)| 00:15:27 | | | Q1,01 | PCWP | |
| 15 | NESTED LOOPS | | 135K| 4893K| 198K (1)| 00:46:19 | | | Q1,01 | PCWP | |
| 16 | BUFFER SORT | | | | | | | | Q1,01 | PCWC | |
| 17 | PX RECEIVE | | | | | | | | Q1,01 | PCWP | |
| 18 | PX SEND BROADCAST | :TQ10000 | | | | | | | | S->P | BROADCAST |
| 19 | SORT UNIQUE | | 6 | 96 | 3 (0)| 00:00:01 | | | | | |
|* 20 | TABLE ACCESS FULL | table 3 | 6 | 96 | 3 (0)| 00:00:01 | | | | | |
| 21 | PX PARTITION HASH ALL | | 65923 | | 207 (1)| 00:00:03 | 1 | 32 | Q1,01 | PCWC | |
|* 22 | INDEX RANGE SCAN | I_table1 | 65923 | | 207 (1)| 00:00:03 | 33 | 64 | Q1,01 | PCWP | |
| 23 | PX BLOCK ITERATOR | | 12M| 201M| 5738 (2)| 00:01:21 | | | Q1,02 | PCWC | |
| 24 | INDEX FAST FULL SCAN | I_table 2 | 12M| 201M| 5738 (2)| 00:01:21 | | | Q1,02 | PCWP | |
此致