2013-05-10感受子查询的威力
把子查询中的in改为exists，改之前是对GG_TASK_FORM_RISK_CTL_LOG全表扫描，改之后是通过表GG_TASK_FORM_RISK_CTL_LOG进行索引扫描，优化前后性能提高了30多倍。注：查出来的数据量为144条数据。
数据规模：
select count(1) from GGA_RISK_BASE_INFO; --2828
select count(1) from GG_TASK_FORM_CLASSTEMPLATE; --5600
select count(1) from GG_TASK_FORM_TEMPLATEVERSION; --7646
select count(1) from GG_TASK_FORM_EXETASKRECORD; --33064
select count(1) from GG_TASK_FORM_RELATIONTEMPLAT; --67319
select count(1) from GG_TASK_FORM_RISK_CTL_LOG;--5210
select count(1) from GG_TASK_FORM_NEW_RISK_INFO;--27831
SELECT *
FROM GGA_RISK_BASE_INFO B,
(SELECT T.BASE_ID, MAX(T.CHANGECOUNT) CHANGECOUNT
FROM (SELECT DISTINCT BI.RISK_BASE_ID BASE_ID,
COUNT(CASE
WHEN (FT.TEMPLATE_VERSION_ID IN
(SELECT CL.TEMPLATE_VERSION_ID
FROM GG_TASK_FORM_RISK_CTL_LOG CL)) THEN
FR.REL_TEMP_ID
ELSE
NULL
END) OVER(PARTITION BY BI.RISK_BASE_ID) + COUNT(CASE
WHEN ((FT.TEMPLATE_VERSION_ID not IN
(SELECT CL.TEMPLATE_VERSION_ID
FROM GG_TASK_FORM_RISK_CTL_LOG CL)) and
FR.REL_TEMP_ID in
(SELECT ri.REL_TEMP_ID
FROM GG_task_form_new_risk_info ri)) THEN
FR.REL_TEMP_ID
ELSE
NULL
END) OVER(PARTITION BY BI.RISK_BASE_ID) CHANGECOUNT
FROM GGA_RISK_BASE_INFO BI,
GG_TASK_FORM_CLASSTEMPLATE FC,
GG_TASK_FORM_TEMPLATEVERSION FT,
GG_TASK_FORM_RELATIONTEMPLAT FR,
GG_TASK_WORK_SHEET WS,
GG_TASK_FORM_EXETASKRECORD FE
WHERE FC.RISK_BASE_ID = BI.RISK_BASE_ID
and FT.TEMPLATE_FID = FC.TEMPLATE_ID
and FR.TEMPLATE_VERSION_ID = FT.TEMPLATE_VERSION_ID
and FR.OBJECT_ID = WS.WORK_SHEET_ID
and FE.REL_TEMP_ID = FR.REL_TEMP_ID
and FR.REL_OBJECT_TYPE = '1'
AND FE.TASK_START_TIME > BI.RISK_ASSESS_TIME) T
WHERE T.CHANGECOUNT > 0
GROUP BY BASE_ID) C
WHERE B.RISK_BASE_ID = C.BASE_ID;
SELECT *
FROM SPRMS_RISK_BASE_INFO B,
(SELECT T.BASE_ID, MAX(T.CHANGECOUNT) CHANGECOUNT
FROM (SELECT DISTINCT BI.RISK_BASE_ID BASE_ID,
COUNT(CASE
WHEN exists (SELECT 1 FROM PROD_TASK_FORM_RISK_CTL_LOG CL
where FT.TEMPLATE_VERSION_ID=CL.TEMPLATE_VERSION_ID) THEN
FR.REL_TEMP_ID
ELSE
NULL
END) OVER(PARTITION BY BI.RISK_BASE_ID) + COUNT(CASE
WHEN (not exists
(SELECT 1
FROM PROD_TASK_FORM_RISK_CTL_LOG CL
where FT.TEMPLATE_VERSION_ID= CL.TEMPLATE_VERSION_ID))
and exists
(SELECT 1 FROM prod_task_form_new_risk_info ri
where FR.REL_TEMP_ID = ri.REL_TEMP_ID) THEN
FR.REL_TEMP_ID
ELSE
NULL
END) OVER(PARTITION BY BI.RISK_BASE_ID) CHANGECOUNT
FROM SPRMS_RISK_BASE_INFO BI,
PROD_TASK_FORM_CLASSTEMPLATE FC,
PROD_TASK_FORM_TEMPLATEVERSION FT,
PROD_TASK_FORM_RELATIONTEMPLAT FR,
PROD_TASK_WORK_SHEET WS,
PROD_TASK_FORM_EXETASKRECORD FE
WHERE FC.RISK_BASE_ID = BI.RISK_BASE_ID
and FT.TEMPLATE_FID = FC.TEMPLATE_ID
and FR.TEMPLATE_VERSION_ID = FT.TEMPLATE_VERSION_ID
and FR.OBJECT_ID = WS.WORK_SHEET_ID
and FE.REL_TEMP_ID = FR.REL_TEMP_ID
and FR.REL_OBJECT_TYPE = '1'
AND FE.TASK_START_TIME > BI.RISK_ASSESS_TIME) T
WHERE T.CHANGECOUNT > 0
GROUP BY BASE_ID) C
WHERE B.RISK_BASE_ID = C.BASE_ID;