这个查询单独执行时需要1秒才能执行相同的查询通过程序执行它需要20秒，请帮我这个
SELECT * FROM
(SELECT TAB1.*,ROWNUM ROWNUMM FROM
(SELECT wh.workitem_id, wh.workitem_priority, wh.workitem_type_id, wt.workitem_type_nm,
wh.workitem_status_id, ws.workitem_status_nm, wh.analyst_group_id,
ag.analyst_group_nm, wh.owner_uuid, earnings_estimate.pr_get_name_from_uuid(owner_uuid) owner_name,
wh.create_user_id, earnings_estimate.pr_get_name_from_uuid( wh.create_user_id) create_name, wh.create_ts,
wh.update_user_id,earnings_estimate.pr_get_name_from_uuid(wh.update_user_id) update_name, wh.update_ts, wh.bb_ticker_id, wh.node_id,
wh.eqcv_analyst_uuid, earnings_estimate.pr_get_name_from_uuid( wh.eqcv_analyst_uuid) eqcv_analyst_name,
WH.WORKITEM_NOTE,Wh.PACKAGE_ID ,Wh.COVERAGE_STATUS_NUM ,CS.COVERAGE_STATUS_CD ,Wh.COVERAGE_REC_NUM,I.INDUSTRY_CD INDUSTRY_CODE,I.INDUSTRY_NM
INDUSTRY_NAME,WOT.WORKITEM_OUTLIER_TYPE_NM as WORKITEM_SUBTYPE_NM
,count(1) over() AS total_count,bro.BB_ID BROKER_BB_ID,bro.BROKER_NM BROKER_NAME, wh.assigned_analyst_uuid,earnings_estimate.pr_get_name_from_uuid(wh.assigned_analyst_uuid)
assigned_analyst_name
FROM earnings_estimate.workitem_type wt,
earnings_estimate.workitem_status ws,
earnings_estimate.workitem_outlier_type wot,
(SELECT * FROM (
SELECT WH.ASSIGNED_ANALYST_UUID,WH.DEFERRED_TO_DT,WH.WORKITEM_NOTE,WH.UPDATE_USER_ID,EARNINGS_ESTIMATE.PR_GET_NAME_FROM_UUID(WH.UPDATE_USER_ID)
UPDATE_NAME, WH.UPDATE_TS,WH.OWNER_UUID, EARNINGS_ESTIMATE.PR_GET_NAME_FROM_UUID(OWNER_UUID)
OWNER_NAME,WH.ANALYST_GROUP_ID,WH.WORKITEM_STATUS_ID,WH.WORKITEM_PRIORITY,EARNINGS_ESTIMATE.PR_GET_NAME_FROM_UUID( WI.CREATE_USER_ID) CREATE_NAME, WI.CREATE_TS,
wi.create_user_id,wi.workitem_type_id,wi.workitem_id,RANK() OVER (PARTITION BY WH.WORKITEM_ID ORDER BY WH.CREATE_TS DESC NULLS LAST, ROWNUM) R,
wo.bb_ticker_id, wo.node_id,wo.eqcv_analyst_uuid,
WO.PACKAGE_ID ,WO.COVERAGE_STATUS_NUM ,WO.COVERAGE_REC_NUM,
wo.workitem_outlier_type_id
FROM earnings_estimate.workitem_history wh
JOIN EARNINGS_ESTIMATE.workitem_outlier wo
ON wh.workitem_id=wo.workitem_id
JOIN earnings_estimate.workitem wi
ON wi.workitem_id=wo.workitem_id
AND WI.WORKITEM_TYPE_ID=3
and wh.workitem_status_id not in (1,7)
WHERE ( wo.bb_ticker_id IN (SELECT
column_value from table(v_tickerlist) )
)
)wh
where r=1
AND DECODE(V_DATE_TYPE,'CreatedDate',WH.CREATE_TS,'LastModifiedDate',WH.UPDATE_TS) >= V_START_DATE
AND decode(v_date_type,'CreatedDate',wh.create_ts,'LastModifiedDate',wh.update_ts) <= v_end_date
and decode(wh.owner_uuid,null,-1,wh.owner_uuid)=decode(v_analyst_id,null,decode(wh.owner_uuid,null,-1,wh.owner_uuid),v_analyst_id)
) wh,
earnings_estimate.analyst_group ag,
earnings_estimate.coverage_status cs,
earnings_estimate.research_document rd,
( SELECT
BB.BB_ID ,
BRK.BROKER_ID,
BRK.BROKER_NM
FROM EARNINGS_ESTIMATE.BROKER BRK,COMMON.BB_ID BB
WHERE BRK.ORG_ID = BB.ORG_ID
AND BRK.ORG_LOC_REC_NUM = BB.ORG_LOC_REC_NUM
AND BRK.primary_broker_ind='Y') bro,
earnings_estimate.industry i
WHERE wh.analyst_group_id = ag.analyst_group_id
AND wh.workitem_status_id = ws.workitem_status_id
AND wh.workitem_type_id = wt.workitem_type_id
AND wh.coverage_status_num=cs.coverage_status_num
AND wh.workitem_outlier_type_id=wot.workitem_outlier_type_id
AND wh.PACKAGE_ID=rd.PACKAGE_ID(+)
AND rd.industry_id=i.industry_id(+)
AND rd.BROKER_BB_ID=bro.BB_ID(+)
ORDER BY wh.create_ts)tab1 )
;
答案 0 :(得分：0)
我同意这个问题很可能与SELECT column_value from table(v_tickerlist)有关。
默认情况下，Oracle估计表函数返回8168行。由于您使用单个值测试查询，因此我假设实际值的数量通常要小得多。与任何预测一样，基数估计总是错误的。但它们至少应该在实际基数的基础上，以便优化器正常工作。
您可以强制Oracle始终使用动态采样检查大小。这将需要更多时间来生成计划，但在这种情况下可能是值得的。
例如：
SQL> --Sample type
SQL> create or replace type v_tickerlist is table of number;
2 /
Type created.
SQL> --Show explain plans
SQL> set autotrace traceonly explain;
SQL> --Default estimate is poor. 8168 estimated, versus 3 actual.
SQL> SELECT column_value from table(v_tickerlist(1,2,3));
Execution Plan
----------------------------------------------------------
Plan hash value: 1748000095
----------------------------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
----------------------------------------------------------------------------------------------
| 0 | SELECT STATEMENT | | 8168 | 16336 | 16 (0)| 00:00:01 |
| 1 | COLLECTION ITERATOR CONSTRUCTOR FETCH| | 8168 | 16336 | 16 (0)| 00:00:01 |
----------------------------------------------------------------------------------------------
SQL> --Estimate is perfect when dynamic sampling is used.
SQL> SELECT /*+ dynamic_sampling(tickerlist, 2) */ column_value
2 from table(v_tickerlist(1,2,3)) tickerlist;
Execution Plan
----------------------------------------------------------
Plan hash value: 1748000095
----------------------------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
----------------------------------------------------------------------------------------------
| 0 | SELECT STATEMENT | | 3 | 6 | 6 (0)| 00:00:01 |
| 1 | COLLECTION ITERATOR CONSTRUCTOR FETCH| | 3 | 6 | 6 (0)| 00:00:01 |
----------------------------------------------------------------------------------------------
Note
-----
- dynamic sampling used for this statement (level=2)
SQL>
如果这没有帮助，请查看您的解释计划（并在此处发布）。找出基数估计最错误的地方，然后试着找出原因。
答案 1 :(得分：-2)
您的查询太大，在批量数据上执行时会花费时间。尝试放置一些非规范化的临时表，在那里提取数据，然后在临时表之间进行连接。这将提高性能。
使用这个独立查询，不要在子查询中传递任何变量，如下面的行...
WHERE（wo.bb_ticker_id IN（选择
中的column_value
table_（v_tickerlist）
此外，外连接将抛出性能..更好地实现非规范化临时表