统计信息未收集引发的MERGE JOIN CARTESIAN
分析最近管理的一个系统的数据库报告看到一条SQL执行6次，平均执行时间为57s。检查了下SQL，发现语句并无错误，从执行计划中的rows=1来看，应该是统计信息没有收集。检查了下user_tables中的统计信息，确认是没有收集。语句执行速度提升了10倍。
SELECT *
FROM (SELECT INNER_TABLE.*, ROWNUM OUTER_TABLE_ROWNUM
FROM (SELECT EXPERIMENTWORK_PACKAGE.EXPERIMENTWORK_PACKAGE_ID,
EXPERIMENT_WORK.WORK_ID,
EXPERIMENT_WORK.STANDARD_PACKAGE_ID,
EXPERIMENT_WORK.PERIOD_PLAN_ID,
EXPERIMENT_WORK.WORK_NAME,
EXPERIMENT_WORK.WORK_CODE,
EXPERIMENT_WORK.SPECIALTY,
EXPERIMENT_WORK.WORK_CHARACTER,
EXPERIMENT_WORK.PLACE_ID,
EXPERIMENT_WORK.PLACE_NAME,
EXPERIMENT_WORK.PLACE_TYPE,
EXPERIMENT_WORK.MASTER,
EXPERIMENT_WORK.MASTER_ID,
EXPERIMENT_WORK.DEPARTMENT_ID,
EXPERIMENT_WORK.DEPARTMENT_NAME,
EXPERIMENT_WORK.DEPARTMENT_CODE,
EXPERIMENT_WORK.WORK_TEAM,
EXPERIMENT_WORK.WORK_TEAM_CODE,
EXPERIMENT_WORK.WORK_TEAM_ID,
EXPERIMENT_WORK.WORK_PEASONS,
EXPERIMENT_WORK.STANDARD_PACKAGE_NAME,
EXPERIMENT_WORK.WORK_DESCR,
EXPERIMENT_WORK.PLAN_FINISH_TIME,
EXPERIMENT_WORK.CREATOR,
EXPERIMENT_WORK.CREATOR_ID,
EXPERIMENT_WORK.CREATE_TIME,
EXPERIMENT_WORK.ACTUAL_START_TIME,
EXPERIMENT_WORK.ACTUAL_FINISH_TIME,
EXPERIMENT_WORK.WORK_RESULT,
EXPERIMENT_WORK.IS_FIELD_WORK,
EXPERIMENT_WORK.BACK_FLAG,
EXPERIMENT_WORK.IS_INTERRUPTED,
EXPERIMENT_WORK.IS_PLANNED,
EXPERIMENT_WORK.FINISH_FLAG,
EXPERIMENT_WORK.QUALIFIED_FLAG,
EXPERIMENT_WORK.DEVICE_STATUS,
EXPERIMENT_WORK.DEVICE_LOCATION,
EXPERIMENT_WORK.STATE,
EXPERIMENT_WORK.REMARK,
EXPERIMENT_WORK.DATA_FROM,
EXPERIMENT _WORK.INSTRUMENT_MODEL,
EXPERIMENT_WORK.PERIOD_UPDATE_STATE,
EXPERIMENT_WORK.IS_NEED_UPDATE,
EXPERIMENT_WORK.IS_DEFECT,
EXPERIMENT_WORK.TYPE,
EXPERIMENT_WORK.LOCATION_ID,
EXPERIMENT_WORK.FUNCTION_LOCATION_NAME,
EXPERIMENT_WORK.BAY_NAME,
EXPERIMENT_WORK.INSTRUMENT_CODE,
EXPERIMENT_WORK.PLAN_BOUND,
EXPERIMENT_WORK.MANAGE_DEPARTMENT_ID,
EXPERIMENT_WORK.MANAGE_DEPARTMENT,
EXPERIMENT_WORK.PLAN_START_TIME,
EXPERIMENT_WORK.WORK_TYPE,
EXPERIMENT_WORK.VEHICLE_NO,
EXPERIMENT_WORK.IS_NEED_VEHICLE,
EXPERIMENT_WORK.CENTER_SUBSTATION_ID,
EXPERIMENT_WORK.CENTER_SUBSTATION_NAME,
EXPERIMENT_WORK.VEHICLE_TIME,
EXPERIMENT_WORK.MEMBER_NUM,
EXPERIMENT_WORK.IS_SHARE_VEHICLE,
EXPERIMENT_WORK.DRIVER,
EXPERIMENT_WORK.DRIVER_ID,
EXPERIMENT_WORK.SHARE_VEHICLE_TEAM,
EXPERIMENT_WORK.CONTACT_WAY,
EXPERIMENT_WORK.SHARE_VEHICLE_TEAM_IDS,
EXPERIMENT_WORK.IS_COMMISSIONED,
EXPERIMENT_WORK.COMMISSION_WORK_ID,
EXPERIMENT_WORK.OBJECT_NUMBER,
EXPERIMENT_WORK.WORK_STATUS,
EXPERIMENT_WORK.IS_NEED_HIGH_VEHICLE,
EXPERIMENT_WORK.HIGH_VEHICLE_DRIVER,
EXPERIMENT_WORK.HIGH_VEHICLE_NO,
EXPERIMENT_WORK.IS_SPECIFICSAFETOOL,
EXPERIMENTWORK_PACKAGE.PACKAGE_NAME,
EXPERIMENTWORK_PACKAGE.IS_PASSED,
EXPERIMENTWORK_PACKAGE.Package_Id,
STANDARD_PACKAGE.VERSION_NO,
RP_EXPERIMENT_ENVIRONMENT.ENVIRONMENT_NAME,
RP_EXPERIMENT_ENVIRONMENT.ENVIRONMEN TL_PLACE,
RP_EXPERIMENT_ENVIRONMENT.ENVIRONMENT_CHARACTER,
RP_EXPERIMENT_ENVIRONMENT.ENVIRONMENT_DATE,
RP_EXPERIMENT_ENVIRONMENT.ENVIRONMENT_CONCLUSION
FROM EXPERIMENT_WORK,
EXPERIMENTWORK_PACKAGE,
RP_EXPERIMENT_ENVIRONMENT,
STANDARD_PACKAGE,
RP_REPORT_INSTANCE_OBJECT
WHERE EXPERIMENT_WORK.WORK_ID =
EXPERIMENTWORK_PACKAGE.WORK_ID
AND RP_REPORT_INSTANCE_OBJECT.EXPERIMENTWORK_PACKAGE_ID =
EXPERIMENTWORK_PACKAGE.EXPERIMENTWORK_PACKAGE_ID
AND RP_REPORT_INSTANCE_OBJECT.REPORT_INSTANCE_OBJECT_ID =
RP_EXPERIMENT_ENVIRONMENT.REPORT_INSTANCE_OBJECT_ID(+)
AND EXPERIMENTWORK_PACKAGE.PACKAGE_ID =
STANDARD_PACKAGE.STANDARD_PACKAGE_ID
AND EXISTS
(SELECT C.CATALOG_ID
FROM STANDARD_CATALOG C
WHERE C.CATALOG_ID = STANDARD_PACKAGE.CATALOG_ID
START WITH C.PARENT_ID = 0
CONNECT BY PRIOR C.CATALOG_ID = C.PARENT_ID)
AND (RP_EXPERIMENT_ENVIRONMENT.ENVIRONMENT_CONCLUSION = :1 OR
RP_EXPERIMENT_ENVIRONMENT.ENVIRONMENT_CONCLUSION = :2)
AND RP_EXPERIMENT_ENVIRONMENT.ENVIRONMENT_CHARACTER like :3
AND STANDARD_PACKAGE.STANDARD_PACKAGE_NO = :4
AND RP_EXPERIMENT_ENVIRONMENT.ENVIRONMENT_DATE >= :5
AND RP_EXPERIMENT_ENVIRONMENT.ENVIRONMENT_DATE <= :6
AND EXPERIMENT_WORK.SPECIALTY = :7
AND EXPERIMENT_WORK.WORK_TEAM_ID = :8
ORDER BY RP_EXPERIMENT_ENVIRONMENT.ENVIRONMENT_DATE asc nulls last) INNER_TABLE
WHERE ROWNUM <= 18) OUTER_TABLE
WHERE OUTER_TABLE_ROWNUM > 0;
已用时间: 00: 00: 06.93
执行计划
--------------------------------------------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)|
----------------------------------------------------------------------------------------------------------
| 0 | SELECT STATEMENT | | 1 | 8520 | 38 (3)|
| 1 | VIEW | | 1 | 8520 | 38 (3)|
| 2 | COUNT STOPKEY | | | | |
| 3 | VIEW | | 1 | 8507 | 38 (3)|
| 4 | SORT ORDER BY STOPKEY | | 1 | 567 | 38 (3)|
| 5 | FILTER | | | | |
| 6 | NESTED LOOPS | | 1 | 567 | 34 (0)|
| 7 | NESTED LOOPS | | 1 | 542 | 33 (0)|
| 8 | MERGE JOIN CARTESIAN | | 1 | 507 | 32 (0)|
| 9 | NESTED LOOPS | | 1 | 119 | 14 (0)|
| 10 | TABLE ACCESS FULL | RP_EXPERIMENT_ENVIRONMENT | 1 | 77 | 13 (0)|
| 11 | TABLE ACCESS BY INDEX ROWID| RP_REPORT_INSTANCE_OBJECT | 1 | 42 | 1 (0)|
| 12 | INDEX UNIQUE SCAN | PK_RP_REPORT_INSTANCE_OBJECT | 1 | | 1 (0)|
| 13 | BUFFER SORT | | 10 | 3880 | 31 (0)|
| 14 | TABLE ACCESS FULL | EXPERIMENT_WORK | 10 | 3880 | 18 (0)|
| 15 | TABLE ACCESS BY INDEX ROWID | EXPERIMENTWORK_PACKAGE | 1 | 35 | 1 (0)|
| 16 | INDEX RANGE SCAN | IDX_WORK_ID | 2 | | 1 (0)|
| 17 | TABLE ACCESS BY INDEX ROWID | STANDARD_PACKAGE | 1 | 25 | 1 (0)|
| 18 | INDEX UNIQUE SCAN | PK_STANDARD_PACKAGE | 1 | | 1 (0)|
| 19 | FILTER | | | | |
| 20 | CONNECT BY WITH FILTERING | | | | |
| 21 | FILTER | | | | |
| 22 | TABLE ACCESS FULL | STANDARD_CATALOG | 192 | 1536 | 3 (0)|
| 23 | HASH JOIN | | | | |
| 24 | CONNECT BY PUMP | | | | |
| 25 | TABLE ACCESS FULL | STANDARD_CATALOG | 192 | 1536 | 3 (0)|
| 26 | TABLE ACCESS FULL | STANDARD_CATALOG | 192 | 1536 | 3 (0)|
----------------------------------------------------------------------------------------------------------
统计信息 ---------------------------------------------------------- 1 recursive calls 0 db block gets 1159757 consistent gets 0 physical reads 0 redo size 6782 bytes sent via SQL*Net to client 5334 bytes received via SQL*Net from client 3 SQL*Net roundtrips to/from client 86 sorts (memory) 0 sorts (disk) 18 rows processed
执行统计信息后
已用时间: 00: 00: 00.68
执行计划
------------------------------------------------------------------------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)|
---------------------------------------------------------------------------------------------------------
| 0 | SELECT STATEMENT | | 1 | 8520 | 497 (2)|
| 1 | VIEW | | 1 | 8520 | 497 (2)|
| 2 | COUNT STOPKEY | | | | |
| 3 | VIEW | | 1 | 8507 | 497 (2)|
| 4 | SORT ORDER BY STOPKEY | | 1 | 618 | 497 (2)|
| 5 | FILTER | | | | |
| 6 | NESTED LOOPS | | 1 | 618 | 493 (1)|
| 7 | HASH JOIN | | 1 | 589 | 492 (1)|
| 8 | TABLE ACCESS FULL | RP_EXPERIMENT_ENVIRONMENT | 8 | 608 | 139 (1)|
| 9 | HASH JOIN | | 1003 | 502K| 352 (1)|
| 10 | NESTED LOOPS | | 997 | 458K| 268 (1)|
| 11 | TABLE ACCESS FULL | EXPERIMENT_WORK | 510 | 214K| 166 (1)|
| 12 | TABLE ACCESS BY INDEX ROWID| EXPERIMENTWORK_PACKAGE | 2 | 82 | 1 (0)|
| 13 | INDEX RANGE SCAN | IDX_WORK_ID | 2 | | 1 (0)|
| 14 | TABLE ACCESS FULL | RP_REPORT_INSTANCE_OBJECT | 24463 | 1003K| 84 (2)|
| 15 | TABLE ACCESS BY INDEX ROWID | STANDARD_PACKAGE | 1 | 29 | 1 (0)|
| 16 | INDEX UNIQUE SCAN | PK_STANDARD_PACKAGE | 1 | | 1 (0)|
| 17 | FILTER | | | | |
| 18 | CONNECT BY WITH FILTERING | | | | |
| 19 | FILTER | | | | |
| 20 | TABLE ACCESS FULL | STANDARD_CATALOG | 218 | 1744 | 3 (0)|
| 21 | HASH JOIN | | | | |
| 22 | CONNECT BY PUMP | | | | |
| 23 | TABLE ACCESS FULL | STANDARD_CATALOG | 218 | 1744 | 3 (0)|
| 24 | TABLE ACCESS FULL | STANDARD_CATALOG | 218 | 1744 | 3 (0)|
-----------------------------------------------------------------------------------------------
统计信息
----------------------------------------------------------
1 recursive calls
0 db block gets
8804 consistent gets
0 physical reads
0 redo size
6811 bytes sent via SQL*Net to client
5334 bytes received via SQL*Net from client
3 SQL*Net roundtrips to/from client
85 sorts (memory)
0 sorts (disk)
18 rows processed