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分公司业务部门同事一直抱怨登录系统、查询数据等操作非常缓慢，问题反馈到开发同事，再到我这里的时候已经相当严重了，而且在日常对数据库进行监控的时候，抓取出来的问题SQL与开发给我的SQL是一致的，该SQL就是频繁导致数据库服务器CPU使用率飙升到90%以上的元凶，所以最近对该SQL进行了优化。
SQL文本如下：（最原始的SQL里有多重distinct，或者类似where 1=1这样的内容，为了节省篇幅，下面是精简后的SQL）
select count(*) from (select distinct t1.* from (select p.c_paid_id as id, p.c_branch_name as organName, p.c_dept_name as daptName, d.project_name as itemName, p.c_Insurance_Com_Name as pryerName, nvl(p.n_Current_Premium, 0) as commission, decode(p.c_Endorsement_Code, null, ‘保单‘, ‘批单‘) as policyType, p.c_Apply_Code as allInsuranceCode, nvl(p.c_insurance_code, lcc.INSURANCE_POLICY_NO) as insuranceCode, p.c_Endorsement_Code as endorsenentCode, decode(p.c_endorsement_code, null, nvl(to_char(lcc.sign_time, ‘yyyy-mm-dd‘), to_char(p.sign_time, ‘yyyy-mm-dd‘)), to_char(ipt.effective_date, ‘yyyy-mm-dd‘)) as signDate, decode(p.c_endorsement_code, null, nvl(to_char(lcc.start_date, ‘yyyy-mm-dd‘), to_char(p.start_date, ‘yyyy-mm-dd‘)), to_char(ipt.start_date, ‘yyyy-mm-dd‘)) as starDate, decode(p.c_endorsement_code, null, nvl(to_char(lcc.end_date, ‘yyyy-mm-dd‘), to_char(p.end_date, ‘yyyy-mm-dd‘)), to_char(ipt.end_date, ‘yyyy-mm-dd‘)) as endDate, to_char(p.d_ddate, ‘yyyy-mm-dd‘) as ddate, decode(se.c_paid_id, null, ‘否‘, ‘是‘) as selletStatus, se.C_PAYMENT_CODE as settlementCode, p.c_is_paid as isSettled, p.C_PERIOD as periodno, p.C_INSURANCE_ID as insuranceId, nvl(p.c_insurant_name, lcc.customer_name) as insuredName from paid_info_target p, lccont_target lcc, d_projects d, prem_payment_detail_target se, insurance_policy_target ipt where p.c_unite_policy = lcc.contno(+) and p.c_project_code = d.project_code(+) and p.C_PAID_ID = se.C_PAID_ID(+) and (p.c_unite_policy = ipt.contno(+) and p.c_endorsement_code = ipt.mli_insurance_endorsement_no(+)) and p.C_INSURANCE_COM_CODE = ‘0001300049.00158‘ and p.c_dept_id = ‘JT015200107‘ and p.c_branch_code = ‘JT0152001‘ and p.c_system_name like ‘%‘ || ‘旅游保险网‘ || ‘%‘ order by lcc.INSURANCE_POLICY_NO desc) t1, import_pay_confirm t2 where t2.c_bath_no = 1 and t2.c_import_by = ‘dx.xie‘ and (t1.allInsuranceCode = t2.c_apply_no or t1.insuranceCode = t2.c_policy_no or t1.endorsenentCode = t2.C_ENDORSEMENT_CODE or t1.insuranceId = t2.C_INSURANCE_ID));
在这里我不想把该SQL的执行计划贴出来，因为我根本就没有保存^-^，而且，切入点并不是从原SQL的执行计划开始。
开始分析该SQL的逻辑：
表import_pay_confirm是从前台页面导入的表，有四个字段，在SQL的最后与t1进行关联。因此我采用union all将该语句改写了，这样就能帮助优化器进行查询改写，视图合并之类的。这是第一个改写的地方
第二个地方是t1中的选择列：
decode((select count(*)
from prem_payment_detail_target
where p.c_paid_id = C_PAID_ID),
0,
‘否‘,
‘是‘) as selletStatus,
改写后的该选择列的表达式为decode(se.c_paid_id, null, ‘否‘, ‘是‘) as selletStatus，因为只是作一个判断，完全可以直接对prem_payment_detail_target表的字段c_paid_id进行判断，这样可以减少对该表的重复访问
改写后的SQL相当长，但是逻辑要简单很多，而且速度快很多，因此也证明了，SQL写的长不一定性能不好，效率不高，SQL短不代表逻辑清晰、性能好，下面是SQL语句与执行计划：
select count(*) from (select distinct t1.* from (select p.c_paid_id as id, p.c_branch_name as organName, p.c_dept_name as daptName, d.project_name as itemName, p.c_Insurance_Com_Name as pryerName, nvl(p.n_Current_Premium, 0) as commission, decode(p.c_Endorsement_Code, null, ‘保单‘, ‘批单‘) as policyType, p.c_Apply_Code as allInsuranceCode, nvl(p.c_insurance_code, lcc.INSURANCE_POLICY_NO) as insuranceCode, p.c_Endorsement_Code as endorsenentCode, decode(p.c_endorsement_code, null, nvl(to_char(lcc.sign_time, ‘yyyy-mm-dd‘), to_char(p.sign_time, ‘yyyy-mm-dd‘)), to_char(ipt.effective_date, ‘yyyy-mm-dd‘)) as signDate, decode(p.c_endorsement_code, null, nvl(to_char(lcc.start_date, ‘yyyy-mm-dd‘), to_char(p.start_date, ‘yyyy-mm-dd‘)), to_char(ipt.start_date, ‘yyyy-mm-dd‘)) as starDate, decode(p.c_endorsement_code, null, nvl(to_char(lcc.end_date, ‘yyyy-mm-dd‘), to_char(p.end_date, ‘yyyy-mm-dd‘)), to_char(ipt.end_date, ‘yyyy-mm-dd‘)) as endDate, to_char(p.d_ddate, ‘yyyy-mm-dd‘) as ddate, decode(se.c_paid_id, null, ‘否‘, ‘是‘) as selletStatus, se.C_PAYMENT_CODE as settlementCode, p.c_is_paid as isSettled, p.C_PERIOD as periodno, p.C_INSURANCE_ID as insuranceId, nvl(p.c_insurant_name, lcc.customer_name) as insuredName from paid_info_target p, lccont_target lcc, d_projects d, prem_payment_detail_target se, insurance_policy_target ipt where p.c_unite_policy = lcc.contno(+) and p.c_project_code = d.project_code(+) and p.C_PAID_ID = se.C_PAID_ID(+) and (p.c_unite_policy = ipt.contno(+) and p.c_endorsement_code = ipt.mli_insurance_endorsement_no(+)) and p.C_INSURANCE_COM_CODE = ‘0001300049.00158‘ and p.c_dept_id = ‘JT015200107‘ and p.c_branch_code = ‘JT0152001‘ and p.c_system_name like ‘%‘ || ‘旅游保险网‘ || ‘%‘ order by lcc.INSURANCE_POLICY_NO desc) t1, import_pay_confirm t2 where t2.c_bath_no = 1 and t1.allInsuranceCode = t2.c_apply_no and t2.c_import_by = ‘dx.xie‘ union all select distinct t1.* from (select p.c_paid_id as id, p.c_branch_name as organName, p.c_dept_name as daptName, d.project_name as itemName, p.c_Insurance_Com_Name as pryerName, nvl(p.n_Current_Premium, 0) as commission, decode(p.c_Endorsement_Code, null, ‘保单‘, ‘批单‘) as policyType, p.c_Apply_Code as allInsuranceCode, nvl(p.c_insurance_code, lcc.INSURANCE_POLICY_NO) as insuranceCode, p.c_Endorsement_Code as endorsenentCode, decode(p.c_endorsement_code, null, nvl(to_char(lcc.sign_time, ‘yyyy-mm-dd‘), to_char(p.sign_time, ‘yyyy-mm-dd‘)), to_char(ipt.effective_date, ‘yyyy-mm-dd‘)) as signDate, decode(p.c_endorsement_code, null, nvl(to_char(lcc.start_date, ‘yyyy-mm-dd‘), to_char(p.start_date, ‘yyyy-mm-dd‘)), to_char(ipt.start_date, ‘yyyy-mm-dd‘)) as starDate, decode(p.c_endorsement_code, null, nvl(to_char(lcc.end_date, ‘yyyy-mm-dd‘), to_char(p.end_date, ‘yyyy-mm-dd‘)), to_char(ipt.end_date, ‘yyyy-mm-dd‘)) as endDate, to_char(p.d_ddate, ‘yyyy-mm-dd‘) as ddate, decode(se.c_paid_id, null, ‘否‘, ‘是‘) as selletStatus, se.C_PAYMENT_CODE as settlementCode, p.c_is_paid as isSettled, p.C_PERIOD as periodno, p.C_INSURANCE_ID as insuranceId, nvl(p.c_insurant_name, lcc.customer_name) as insuredName from paid_info_target p, lccont_target lcc, d_projects d, prem_payment_detail_target se, insurance_policy_target ipt where p.c_unite_policy = lcc.contno(+) and p.c_project_code = d.project_code(+) and p.C_PAID_ID = se.C_PAID_ID(+) and (p.c_unite_policy = ipt.contno(+) and p.c_endorsement_code = ipt.mli_insurance_endorsement_no(+)) and p.C_INSURANCE_COM_CODE = ‘0001300049.00158‘ and p.c_dept_id = ‘JT015200107‘ and p.c_branch_code = ‘JT0152001‘ and p.c_system_name like ‘%‘ || ‘旅游保险网‘ || ‘%‘ order by lcc.INSURANCE_POLICY_NO desc) t1, import_pay_confirm t2 where t2.c_bath_no = 1 and t1.insuranceCode = t2.c_policy_no and t2.c_import_by = ‘dx.xie‘ and t2.c_apply_no is null union all select distinct t1.* from (select p.c_paid_id as id, p.c_branch_name as organName, p.c_dept_name as daptName, d.project_name as itemName, p.c_Insurance_Com_Name as pryerName, nvl(p.n_Current_Premium, 0) as commission, decode(p.c_Endorsement_Code, null, ‘保单‘, ‘批单‘) as policyType, p.c_Apply_Code as allInsuranceCode, nvl(p.c_insurance_code, lcc.INSURANCE_POLICY_NO) as insuranceCode, p.c_Endorsement_Code as endorsenentCode, decode(p.c_endorsement_code, null, nvl(to_char(lcc.sign_time, ‘yyyy-mm-dd‘), to_char(p.sign_time, ‘yyyy-mm-dd‘)), to_char(ipt.effective_date, ‘yyyy-mm-dd‘)) as signDate, decode(p.c_endorsement_code, null, nvl(to_char(lcc.start_date, ‘yyyy-mm-dd‘), to_char(p.start_date, ‘yyyy-mm-dd‘)), to_char(ipt.start_date, ‘yyyy-mm-dd‘)) as starDate, decode(p.c_endorsement_code, null, nvl(to_char(lcc.end_date, ‘yyyy-mm-dd‘), to_char(p.end_date, ‘yyyy-mm-dd‘)), to_char(ipt.end_date, ‘yyyy-mm-dd‘)) as endDate, to_char(p.d_ddate, ‘yyyy-mm-dd‘) as ddate, decode(se.c_paid_id, null, ‘否‘, ‘是‘) as selletStatus, se.C_PAYMENT_CODE as settlementCode, p.c_is_paid as isSettled, p.C_PERIOD as periodno, p.C_INSURANCE_ID as insuranceId, nvl(p.c_insurant_name, lcc.customer_name) as insuredName from paid_info_target p, lccont_target lcc, d_projects d, prem_payment_detail_target se, insurance_policy_target ipt where p.c_unite_policy = lcc.contno(+) and p.c_project_code = d.project_code(+) and p.C_PAID_ID = se.C_PAID_ID(+) and (p.c_unite_policy = ipt.contno(+) and p.c_endorsement_code = ipt.mli_insurance_endorsement_no(+)) and p.C_INSURANCE_COM_CODE = ‘0001300049.00158‘ and p.c_dept_id = ‘JT015200107‘ and p.c_branch_code = ‘JT0152001‘ and p.c_system_name like ‘%‘ || ‘旅游保险网‘ || ‘%‘ order by lcc.INSURANCE_POLICY_NO desc) t1, import_pay_confirm t2 where t2.c_bath_no = 1 and t1.endorsenentCode = t2.C_ENDORSEMENT_CODE and t2.c_import_by = ‘dx.xie‘ and t2.c_policy_no is null and t2.c_apply_no is null union all select distinct t1.* from (select p.c_paid_id as id, p.c_branch_name as organName, p.c_dept_name as daptName, d.project_name as itemName, p.c_Insurance_Com_Name as pryerName, nvl(p.n_Current_Premium, 0) as commission, decode(p.c_Endorsement_Code, null, ‘保单‘, ‘批单‘) as policyType, p.c_Apply_Code as allInsuranceCode, nvl(p.c_insurance_code, lcc.INSURANCE_POLICY_NO) as insuranceCode, p.c_Endorsement_Code as endorsenentCode, decode(p.c_endorsement_code, null, nvl(to_char(lcc.sign_time, ‘yyyy-mm-dd‘), to_char(p.sign_time, ‘yyyy-mm-dd‘)), to_char(ipt.effective_date, ‘yyyy-mm-dd‘)) as signDate, decode(p.c_endorsement_code, null, nvl(to_char(lcc.start_date, ‘yyyy-mm-dd‘), to_char(p.start_date, ‘yyyy-mm-dd‘)), to_char(ipt.start_date, ‘yyyy-mm-dd‘)) as starDate, decode(p.c_endorsement_code, null, nvl(to_char(lcc.end_date, ‘yyyy-mm-dd‘), to_char(p.end_date, ‘yyyy-mm-dd‘)), to_char(ipt.end_date, ‘yyyy-mm-dd‘)) as endDate, to_char(p.d_ddate, ‘yyyy-mm-dd‘) as ddate, decode(se.c_paid_id, null, ‘否‘, ‘是‘) as selletStatus, se.C_PAYMENT_CODE as settlementCode, p.c_is_paid as isSettled, p.C_PERIOD as periodno, p.C_INSURANCE_ID as insuranceId, nvl(p.c_insurant_name, lcc.customer_name) as insuredName from paid_info_target p, lccont_target lcc, d_projects d, prem_payment_detail_target se, insurance_policy_target ipt where p.c_unite_policy = lcc.contno(+) and p.c_project_code = d.project_code(+) and p.C_PAID_ID = se.C_PAID_ID(+) and (p.c_unite_policy = ipt.contno(+) and p.c_endorsement_code = ipt.mli_insurance_endorsement_no(+)) and p.C_INSURANCE_COM_CODE = 0001300049.00158 and p.c_dept_id = ‘JT015200107‘ and p.c_branch_code = ‘JT0152001‘ and p.c_system_name like ‘%‘ || ‘旅游保险网‘ || ‘%‘ order by lcc.INSURANCE_POLICY_NO desc) t1, import_pay_confirm t2 where t2.c_bath_no = 1 and t1.insuranceId = t2.C_INSURANCE_ID and t2.c_import_by = ‘dx.xie‘ and t2.c_policy_no is null and t2.c_apply_no is null and t2.C_ENDORSEMENT_CODE is null); ------------------------------------- SQL_ID brut29q5yb2j5, child number 1 ------------------------------------- Plan hash value: 3456365982 ------------------------------------------------------------------------------------------------------------------------------------------------------------- | Id | Operation | Name | Starts | E-Rows | A-Rows | A-Time | Buffers | OMem | 1Mem | Used-Mem | ------------------------------------------------------------------------------------------------------------------------------------------------------------- | 0 | SELECT STATEMENT | | 1 | | 1 |00:00:00.79 | 142K| | | | | 1 | SORT AGGREGATE | | 1 | 1 | 1 |00:00:00.79 | 142K| | | | | 2 | VIEW | | 1 | 4 | 165 |00:00:00.79 | 142K| | | | | 3 | UNION-ALL | | 1 | | 165 |00:00:00.79 | 142K| | | | | 4 | HASH UNIQUE | | 1 | 1 | 165 |00:00:00.02 | 3274 | 698K| 698K| 636K (0)| | 5 | NESTED LOOPS OUTER | | 1 | 1 | 165 |00:00:00.02 | 2942 | | | | | 6 | NESTED LOOPS OUTER | | 1 | 1 | 165 |00:00:00.01 | 2445 | | | | | 7 | NESTED LOOPS OUTER | | 1 | 1 | 165 |00:00:00.01 | 2441 | | | | | 8 | NESTED LOOPS OUTER | | 1 | 1 | 165 |00:00:00.01 | 1954 | | | | | 9 | NESTED LOOPS | | 1 | 1 | 165 |00:00:00.01 | 1622 | | | | |* 10 | TABLE ACCESS FULL | IMPORT_PAY_CONFIRM | 1 | 181 | 164 |00:00:00.01 | 374 | | | | |* 11 | TABLE ACCESS BY INDEX ROWID | PAID_INFO_TARGET | 164 | 1 | 165 |00:00:00.01 | 1248 | | | | |* 12 | INDEX RANGE SCAN | INDEX_PAID_5 | 164 | 1 | 990 |00:00:00.01 | 496 | | | | | 13 | TABLE ACCESS BY INDEX ROWID | D_PROJECTS | 165 | 1 | 165 |00:00:00.01 | 332 | | | | |* 14 | INDEX RANGE SCAN | INDEX_D_PROJECTS_1 | 165 | 1 | 165 |00:00:00.01 | 167 | | | | | 15 | TABLE ACCESS BY INDEX ROWID | LCCONT_TARGET | 165 | 1 | 153 |00:00:00.01 | 487 | | | | |* 16 | INDEX RANGE SCAN | INDEX_LCCONT_CONTNO | 165 | 1 | 153 |00:00:00.01 | 334 | | | | |* 17 | TABLE ACCESS BY INDEX ROWID | INSURANCE_POLICY_TARGET | 165 | 1 | 1 |00:00:00.01 | 4 | | | | |* 18 | INDEX RANGE SCAN | INDEX_INSUE_POLICY_1 | 165 | 1 | 1 |00:00:00.01 | 3 | | | | | 19 | TABLE ACCESS BY INDEX ROWID | PREM_PAYMENT_DETAIL_TARGET | 165 | 1 | 165 |00:00:00.01 | 497 | | | | |* 20 | INDEX RANGE SCAN | INDEX_PREM_DETAIL_1 | 165 | 1 | 165 |00:00:00.01 | 332 | | | | | 21 | HASH UNIQUE | | 1 | 1 | 0 |00:00:00.59 | 102K| 687K| 687K| | |* 22 | TABLE ACCESS BY INDEX ROWID | IMPORT_PAY_CONFIRM | 1 | 1 | 0 |00:00:00.59 | 102K| | | | | 23 | NESTED LOOPS | | 1 | 1 | 11013 |00:00:00.58 | 102K| | | | | 24 | NESTED LOOPS OUTER | | 1 | 1 | 11012 |00:00:00.53 | 90797 | | | | | 25 | NESTED LOOPS OUTER | | 1 | 1 | 11012 |00:00:00.43 | 66037 | | | | | 26 | NESTED LOOPS OUTER | | 1 | 1 | 11012 |00:00:00.39 | 66031 | | | | | 27 | NESTED LOOPS OUTER | | 1 | 1 | 11012 |00:00:00.23 | 32825 | | | | | 28 | TABLE ACCESS BY INDEX ROWID | PAID_INFO_TARGET | 1 | 1 | 11012 |00:00:00.09 | 10800 | | | | |* 29 | INDEX SKIP SCAN | INDEX_PAID_6 | 1 | 1 | 11012 |00:00:00.02 | 233 | | | | | 30 | TABLE ACCESS BY INDEX ROWID | D_PROJECTS | 11012 | 1 | 11011 |00:00:00.13 | 22025 | | | | |* 31 | INDEX RANGE SCAN | INDEX_D_PROJECTS_1 | 11012 | 1 | 11011 |00:00:00.06 | 11014 | | | | | 32 | TABLE ACCESS BY INDEX ROWID | LCCONT_TARGET | 11012 | 1 | 10996 |00:00:00.15 | 33206 | | | | |* 33 | INDEX RANGE SCAN | INDEX_LCCONT_CONTNO | 11012 | 1 | 10996 |00:00:00.09 | 22210 | | | | |* 34 | TABLE ACCESS BY INDEX ROWID | INSURANCE_POLICY_TARGET | 11012 | 1 | 1 |00:00:00.03 | 6 | | | | |* 35 | INDEX RANGE SCAN | INDEX_INSUE_POLICY_1 | 11012 | 1 | 1 |00:00:00.01 | 5 | | | | | 36 | TABLE ACCESS BY INDEX ROWID | PREM_PAYMENT_DETAIL_TARGET | 11012 | 1 | 179 |00:00:00.09 | 24760 | | | | |* 37 | INDEX RANGE SCAN | INDEX_PREM_DETAIL_1 | 11012 | 1 | 179 |00:00:00.07 | 24581 | | | | |* 38 | INDEX RANGE SCAN | INDEX_NAME3 | 11012 | 2 | 0 |00:00:00.05 | 11259 | | | | | 39 | HASH UNIQUE | | 1 | 1 | 0 |00:00:00.01 | 3 | 687K| 687K| | | 40 | NESTED LOOPS OUTER | | 1 | 1 | 0 |00:00:00.01 | 3 | | | | | 41 | NESTED LOOPS OUTER | | 1 | 1 | 0 |00:00:00.01 | 3 | | | | | 42 | NESTED LOOPS OUTER | | 1 | 1 | 0 |00:00:00.01 | 3 | | | | | 43 | NESTED LOOPS OUTER | | 1 | 1 | 0 |00:00:00.01 | 3 | | | | | 44 | NESTED LOOPS | | 1 | 1 | 0 |00:00:00.01 | 3 | | | | |* 45 | TABLE ACCESS BY INDEX ROWID | IMPORT_PAY_CONFIRM | 1 | 1 | 0 |00:00:00.01 | 3 | | | | |* 46 | INDEX FULL SCAN | INDEX_NAME2 | 1 | 4 | 4 |00:00:00.01 | 1 | | | | |* 47 | TABLE ACCESS BY INDEX ROWID | PAID_INFO_TARGET | 0 | 1 | 0 |00:00:00.01 | 0 | | | | | 48 | BITMAP CONVERSION TO ROWIDS | | 0 | | 0 |00:00:00.01 | 0 | | | | | 49 | BITMAP AND | | 0 | | 0 |00:00:00.01 | 0 | | | | | 50 | BITMAP CONVERSION FROM ROWIDS| | 0 | | 0 |00:00:00.01 | 0 | | | | |* 51 | INDEX RANGE SCAN | INDEX_PAID_2 | 0 | 655 | 0 |00:00:00.01 | 0 | | | | | 52 | BITMAP CONVERSION FROM ROWIDS| | 0 | | 0 |00:00:00.01 | 0 | | | | |* 53 | INDEX RANGE SCAN | INDEX_PAID_4 | 0 | 655 | 0 |00:00:00.01 | 0 | | | | | 54 | TABLE ACCESS BY INDEX ROWID | D_PROJECTS | 0 | 1 | 0 |00:00:00.01 | 0 | | | | |* 55 | INDEX RANGE SCAN | INDEX_D_PROJECTS_1 | 0 | 1 | 0 |00:00:00.01 | 0 | | | | | 56 | TABLE ACCESS BY INDEX ROWID | LCCONT_TARGET | 0 | 1 | 0 |00:00:00.01 | 0 | | | | |* 57 | INDEX RANGE SCAN | INDEX_LCCONT_CONTNO | 0 | 1 | 0 |00:00:00.01 | 0 | | | | |* 58 | TABLE ACCESS BY INDEX ROWID | INSURANCE_POLICY_TARGET | 0 | 1 | 0 |00:00:00.01 | 0 | | | | |* 59 | INDEX RANGE SCAN | INDEX_INSUE_POLICY_1 | 0 | 1 | 0 |00:00:00.01 | 0 | | | | | 60 | TABLE ACCESS BY INDEX ROWID | PREM_PAYMENT_DETAIL_TARGET | 0 | 1 | 0 |00:00:00.01 | 0 | | | | |* 61 | INDEX RANGE SCAN | INDEX_PREM_DETAIL_1 | 0 | 1 | 0 |00:00:00.01 | 0 | | | | | 62 | HASH UNIQUE | | 1 | 1 | 0 |00:00:00.18 | 37509 | 687K| 687K| | | 63 | NESTED LOOPS OUTER | | 1 | 1 | 0 |00:00:00.18 | 37509 | | | | | 64 | NESTED LOOPS OUTER | | 1 | 1 | 0 |00:00:00.18 | 37509 | | | | | 65 | NESTED LOOPS OUTER | | 1 | 1 | 0 |00:00:00.18 | 37509 | | | | | 66 | NESTED LOOPS OUTER | | 1 | 1 | 0 |00:00:00.18 | 37509 | | | | | 67 | NESTED LOOPS | | 1 | 1 | 0 |00:00:00.18 | 37509 | | | | |* 68 | TABLE ACCESS BY INDEX ROWID | PAID_INFO_TARGET | 1 | 1 | 11012 |00:00:00.10 | 15483 | | | | |* 69 | INDEX RANGE SCAN | INDEX_PAID_4 | 1 | 17956 | 17480 |00:00:00.01 | 104 | | | | |* 70 | TABLE ACCESS BY INDEX ROWID | IMPORT_PAY_CONFIRM | 11012 | 1 | 0 |00:00:00.06 | 22026 | | | | |* 71 | INDEX RANGE SCAN | INDEX_NAME4 | 11012 | 1 | 0 |00:00:00.05 | 22026 | | | | | 72 | TABLE ACCESS BY INDEX ROWID | D_PROJECTS | 0 | 1 | 0 |00:00:00.01 | 0 | | | | |* 73 | INDEX RANGE SCAN | INDEX_D_PROJECTS_1 | 0 | 1 | 0 |00:00:00.01 | 0 | | | | | 74 | TABLE ACCESS BY INDEX ROWID | LCCONT_TARGET | 0 | 1 | 0 |00:00:00.01 | 0 | | | | |* 75 | INDEX RANGE SCAN | INDEX_LCCONT_CONTNO | 0 | 1 | 0 |00:00:00.01 | 0 | | | | |* 76 | TABLE ACCESS BY INDEX ROWID | INSURANCE_POLICY_TARGET | 0 | 1 | 0 |00:00:00.01 | 0 | | | | |* 77 | INDEX RANGE SCAN | INDEX_INSUE_POLICY_1 | 0 | 1 | 0 |00:00:00.01 | 0 | | | | | 78 | TABLE ACCESS BY INDEX ROWID | PREM_PAYMENT_DETAIL_TARGET | 0 | 1 | 0 |00:00:00.01 | 0 | | | | |* 79 | INDEX RANGE SCAN | INDEX_PREM_DETAIL_1 | 0 | 1 | 0 |00:00:00.01 | 0 | | | | ------------------------------------------------------------------------------------------------------------------------------------------------------------- Predicate Information (identified by operation id): --------------------------------------------------- 10 - filter(("T2"."C_IMPORT_BY"=‘dx.xie‘ AND "T2"."C_APPLY_NO" IS NOT NULL AND "T2"."C_BATH_NO"=1)) 11 - filter(("P"."C_INSURANCE_COM_CODE"=‘0001300049.00158‘ AND "P"."C_DEPT_ID"=‘JT015200107‘ AND "P"."C_BRANCH_CODE"=‘JT0152001‘ AND "P"."C_SYSTEM_NAME" LIKE ‘%旅游保险网%‘ AND "P"."C_SYSTEM_NAME" IS NOT NULL)) 12 - access("P"."C_APPLY_CODE"="T2"."C_APPLY_NO") 14 - access("P"."C_PROJECT_CODE"="D"."PROJECT_CODE") 16 - access("P"."C_UNITE_POLICY"="LCC"."CONTNO") 17 - filter("P"."C_UNITE_POLICY"="IPT"."CONTNO") 18 - access("P"."C_ENDORSEMENT_CODE"="IPT"."MLI_INSURANCE_ENDORSEMENT_NO") 20 - access("P"."C_PAID_ID"="SE"."C_PAID_ID") 22 - filter(("T2"."C_APPLY_NO" IS NULL AND "T2"."C_IMPORT_BY"=‘dx.xie‘ AND "T2"."C_BATH_NO"=1)) 29 - access("P"."C_BRANCH_CODE"=‘JT0152001‘ AND "P"."C_DEPT_ID"=‘JT015200107‘ AND "P"."C_INSURANCE_COM_CODE"=‘0001300049.00158‘) filter(("P"."C_INSURANCE_COM_CODE"=‘0001300049.00158‘ AND "P"."C_DEPT_ID"=‘JT015200107‘ AND "P"."C_BRANCH_CODE"=‘JT0152001‘ AND "P"."C_SYSTEM_NAME" LIKE ‘%旅游保险网%‘ AND "P"."C_SYSTEM_NAME" IS NOT NULL)) 31 - access("P"."C_PROJECT_CODE"="D"."PROJECT_CODE") 33 - access("P"."C_UNITE_POLICY"="LCC"."CONTNO") 34 - filter("P"."C_UNITE_POLICY"="IPT"."CONTNO") 35 - access("P"."C_ENDORSEMENT_CODE"="IPT"."MLI_INSURANCE_ENDORSEMENT_NO") 37 - access("P"."C_PAID_ID"="SE"."C_PAID_ID") 38 - access("T2"."C_POLICY_NO"=NVL("P"."C_INSURANCE_CODE","LCC"."INSURANCE_POLICY_NO")) 45 - filter(("T2"."C_APPLY_NO" IS NULL AND "T2"."C_IMPORT_BY"=‘dx.xie‘ AND "T2"."C_POLICY_NO" IS NULL AND "T2"."C_BATH_NO"=1)) 46 - filter("T2"."C_ENDORSEMENT_CODE" IS NOT NULL) 47 - filter(("P"."C_INSURANCE_COM_CODE"=‘0001300049.00158‘ AND "P"."C_BRANCH_CODE"=‘JT0152001‘ AND "P"."C_SYSTEM_NAME" LIKE ‘%旅游保险网%‘ AND "P"."C_SYSTEM_NAME" IS NOT NULL)) 51 - access("P"."C_ENDORSEMENT_CODE"="T2"."C_ENDORSEMENT_CODE") filter("P"."C_ENDORSEMENT_CODE" IS NOT NULL) 53 - access("P"."C_DEPT_ID"=‘JT015200107‘) 55 - access("P"."C_PROJECT_CODE"="D"."PROJECT_CODE") 57 - access("P"."C_UNITE_POLICY"="LCC"."CONTNO") 58 - filter("P"."C_UNITE_POLICY"="IPT"."CONTNO") 59 - access("P"."C_ENDORSEMENT_CODE"="IPT"."MLI_INSURANCE_ENDORSEMENT_NO") 61 - access("P"."C_PAID_ID"="SE"."C_PAID_ID") 68 - filter(("P"."C_BRANCH_CODE"=‘JT0152001‘ AND "P"."C_SYSTEM_NAME" LIKE ‘%旅游保险网%‘ AND TO_NUMBER("P"."C_INSURANCE_COM_CODE")=1300049.00158 AND "P"."C_SYSTEM_NAME" IS NOT NULL)) 69 - access("P"."C_DEPT_ID"=‘JT015200107‘) 70 - filter(("T2"."C_APPLY_NO" IS NULL AND "T2"."C_IMPORT_BY"=‘dx.xie‘ AND "T2"."C_POLICY_NO" IS NULL AND "T2"."C_ENDORSEMENT_CODE" IS NULL AND "T2"."C_BATH_NO"=1)) 71 - access("P"."C_INSURANCE_ID"="T2"."C_INSURANCE_ID") filter("T2"."C_INSURANCE_ID" IS NOT NULL) 73 - access("P"."C_PROJECT_CODE"="D"."PROJECT_CODE") 75 - access("P"."C_UNITE_POLICY"="LCC"."CONTNO") 76 - filter("P"."C_UNITE_POLICY"="IPT"."CONTNO") 77 - access("P"."C_ENDORSEMENT_CODE"="IPT"."MLI_INSURANCE_ENDORSEMENT_NO") 79 - access("P"."C_PAID_ID"="SE"."C_PAID_ID") 144 rows selected.
经过近三天的分析与改写，该SQL第二次执行消耗时间从五分钟降至0.5秒左右，实际返回100多行数据，其消耗的buffer高达142K，假设并发访问很高，必然导致大量的latch：Cache buffer Chain，而且由于服务器物理内存较少，因此如果需要访问的block被踢出SGA
那么第一次访问将会非常缓慢，同时伴随着大量的latch：Cache buffer Chain，随后出现的问题，证明了我的观点，这里我不打算把相关等待事件贴出来，因为我根本就没有保存，我们并不需要去研究这个等待事件的内部机制，只要知道其产生的原因是什么。优化后的第二天早上对数据库进行巡检发现RAC节点1的CPU使用率高达90%，证实了我的猜测，中途找SQL的过程就不细说了，下面继续优化该SQL。
经过对上述执行计划进行分析。发现第二和第四个环节消耗的buffer较大，首先对第二段进行优化与分析。SQL语句进行到这个阶段，优化器同样对视图T1进行了视图合并，通过第38步可以看到：
access("T2"."C_POLICY_NO"=NVL("P"."C_INSURANCE_CODE","LCC"."INSURANCE_POLICY_NO"))，NVL函数的使用抑制了对表paid_info_target和表lccont_target上索引的访问。因此我对这一段进行了改写，同时，对第四段进行优化的方法是添加了相关索引，这里就不进行叙述了，改写后的SQL和执行计划如下：
select count(*) from (select distinct t1.* from (select p.c_paid_id as id, p.c_branch_name as organName, p.c_dept_name as daptName, d.project_name as itemName, p.c_Insurance_Com_Name as pryerName, nvl(p.n_Current_Premium, 0) as commission, decode(p.c_Endorsement_Code, null, ‘保单‘, ‘批单‘) as policyType, p.c_Apply_Code as allInsuranceCode, nvl(p.c_insurance_code, lcc.INSURANCE_POLICY_NO) as insuranceCode, p.c_Endorsement_Code as endorsenentCode, decode(p.c_endorsement_code, null, nvl(to_char(lcc.sign_time, ‘yyyy-mm-dd‘), to_char(p.sign_time, ‘yyyy-mm-dd‘)), to_char(ipt.effective_date, ‘yyyy-mm-dd‘)) as signDate, decode(p.c_endorsement_code, null, nvl(to_char(lcc.start_date, ‘yyyy-mm-dd‘), to_char(p.start_date, ‘yyyy-mm-dd‘)), to_char(ipt.start_date, ‘yyyy-mm-dd‘)) as starDate, decode(p.c_endorsement_code, null, nvl(to_char(lcc.end_date, ‘yyyy-mm-dd‘), to_char(p.end_date, ‘yyyy-mm-dd‘)), to_char(ipt.end_date, ‘yyyy-mm-dd‘)) as endDate, to_char(p.d_ddate, ‘yyyy-mm-dd‘) as ddate, decode(se.c_paid_id, null, ‘否‘, ‘是‘) as selletStatus, se.C_PAYMENT_CODE as settlementCode, p.c_is_paid as isSettled, p.C_PERIOD as periodno, p.C_INSURANCE_ID as insuranceId, nvl(p.c_insurant_name, lcc.customer_name) as insuredName from paid_info_target p, lccont_target lcc, d_projects d, prem_payment_detail_target se, insurance_policy_target ipt where p.c_unite_policy = lcc.contno(+) and p.c_project_code = d.project_code(+) and p.C_PAID_ID = se.C_PAID_ID(+) and (p.c_unite_policy = ipt.contno(+) and p.c_endorsement_code = ipt.mli_insurance_endorsement_no(+)) and p.C_INSURANCE_COM_CODE = ‘0001300049.00158‘ and p.c_dept_id = ‘JT015200107‘ and p.c_branch_code = ‘JT0152001‘ and p.c_system_name like ‘%‘ || ‘旅游保险网‘ || ‘%‘ order by lcc.INSURANCE_POLICY_NO desc) t1, import_pay_confirm t2 where t2.c_bath_no = 1 and t1.allInsuranceCode = t2.c_apply_no and t2.c_import_by = ‘dx.xie‘ union all select distinct t1.* from (select p.c_paid_id as id, p.c_branch_name as organName, p.c_dept_name as daptName, d.project_name as itemName, p.c_Insurance_Com_Name as pryerName, nvl(p.n_Current_Premium, 0) as commission, decode(p.c_Endorsement_Code, null, ‘保单‘, ‘批单‘) as policyType, p.c_Apply_Code as allInsuranceCode, p.c_insurance_code as insuranceCode, p.c_Endorsement_Code as endorsenentCode, decode(p.c_endorsement_code, null, nvl(to_char(lcc.sign_time, ‘yyyy-mm-dd‘), to_char(p.sign_time, ‘yyyy-mm-dd‘)), to_char(ipt.effective_date, ‘yyyy-mm-dd‘)) as signDate, decode(p.c_endorsement_code, null, nvl(to_char(lcc.start_date, ‘yyyy-mm-dd‘), to_char(p.start_date, ‘yyyy-mm-dd‘)), to_char(ipt.start_date, ‘yyyy-mm-dd‘)) as starDate, decode(p.c_endorsement_code, null, nvl(to_char(lcc.end_date, ‘yyyy-mm-dd‘), to_char(p.end_date, ‘yyyy-mm-dd‘)), to_char(ipt.end_date, ‘yyyy-mm-dd‘)) as endDate, to_char(p.d_ddate, ‘yyyy-mm-dd‘) as ddate, decode(se.c_paid_id, null, ‘否‘, ‘是‘) as selletStatus, se.C_PAYMENT_CODE as settlementCode, p.c_is_paid as isSettled, p.C_PERIOD as periodno, p.C_INSURANCE_ID as insuranceId, nvl(p.c_insurant_name, lcc.customer_name) as insuredName from paid_info_target p, lccont_target lcc, d_projects d, prem_payment_detail_target se, insurance_policy_target ipt where p.c_unite_policy = lcc.contno(+) and p.c_project_code = d.project_code(+) and p.C_PAID_ID = se.C_PAID_ID(+) and (p.c_unite_policy = ipt.contno(+) and p.c_endorsement_code = ipt.mli_insurance_endorsement_no(+)) and p.C_INSURANCE_COM_CODE = ‘0001300049.00158‘ and p.c_dept_id = ‘JT015200107‘ and p.c_branch_code = ‘JT0152001‘ and p.c_system_name like ‘%‘ || ‘旅游保险网‘ || ‘%‘ and p.c_insurance_code is not null order by lcc.INSURANCE_POLICY_NO desc) t1, import_pay_confirm t2 where t2.c_bath_no = 1 and t1.insuranceCode = t2.c_policy_no and t2.c_import_by = ‘dx.xie‘ and t2.c_apply_no is null union all select distinct t1.* from (select p.c_paid_id as id, p.c_branch_name as organName, p.c_dept_name as daptName, d.project_name as itemName, p.c_Insurance_Com_Name as pryerName, nvl(p.n_Current_Premium, 0) as commission, decode(p.c_Endorsement_Code, null, ‘保单‘, ‘批单‘) as policyType, p.c_Apply_Code as allInsuranceCode, lcc.INSURANCE_POLICY_NO as insuranceCode, p.c_Endorsement_Code as endorsenentCode, decode(p.c_endorsement_code, null, nvl(to_char(lcc.sign_time, ‘yyyy-mm-dd‘), to_char(p.sign_time, ‘yyyy-mm-dd‘)), to_char(ipt.effective_date, ‘yyyy-mm-dd‘)) as signDate, decode(p.c_endorsement_code, null, nvl(to_char(lcc.start_date, ‘yyyy-mm-dd‘), to_char(p.start_date, ‘yyyy-mm-dd‘)), to_char(ipt.start_date, ‘yyyy-mm-dd‘)) as starDate, decode(p.c_endorsement_code, null, nvl(to_char(lcc.end_date, ‘yyyy-mm-dd‘), to_char(p.end_date, ‘yyyy-mm-dd‘)), to_char(ipt.end_date, ‘yyyy-mm-dd‘)) as endDate, to_char(p.d_ddate, ‘yyyy-mm-dd‘) as ddate, decode(se.c_paid_id, null, ‘否‘, ‘是‘) as selletStatus, se.C_PAYMENT_CODE as settlementCode, p.c_is_paid as isSettled, p.C_PERIOD as periodno, p.C_INSURANCE_ID as insuranceId, nvl(p.c_insurant_name, lcc.customer_name) as insuredName from paid_info_target p, lccont_target lcc, d_projects d, prem_payment_detail_target se, insurance_policy_target ipt where p.c_unite_policy = lcc.contno(+) and p.c_project_code = d.project_code(+) and p.C_PAID_ID = se.C_PAID_ID(+) and (p.c_unite_policy = ipt.contno(+) and p.c_endorsement_code = ipt.mli_insurance_endorsement_no(+)) and p.C_INSURANCE_COM_CODE = ‘0001300049.00158‘ and p.c_dept_id = ‘JT015200107‘ and p.c_branch_code = ‘JT0152001‘ and p.c_system_name like ‘%‘ || ‘旅游保险网‘ || ‘%‘ and p.c_insurance_code is null order by lcc.INSURANCE_POLICY_NO desc) t1, import_pay_confirm t2 where t2.c_bath_no = 1 and t1.insuranceCode = t2.c_policy_no and t2.c_import_by = ‘dx.xie‘ and t2.c_apply_no is null union all select distinct t1.* from (select p.c_paid_id as id, p.c_branch_name as organName, p.c_dept_name as daptName, d.project_name as itemName, p.c_Insurance_Com_Name as pryerName, nvl(p.n_Current_Premium, 0) as commission, decode(p.c_Endorsement_Code, null, ‘保单‘, ‘批单‘) as policyType, p.c_Apply_Code as allInsuranceCode, nvl(p.c_insurance_code, lcc.INSURANCE_POLICY_NO) as insuranceCode, p.c_Endorsement_Code as endorsenentCode, decode(p.c_endorsement_code, null, nvl(to_char(lcc.sign_time, ‘yyyy-mm-dd‘), to_char(p.sign_time, ‘yyyy-mm-dd‘)), to_char(ipt.effective_date, ‘yyyy-mm-dd‘)) as signDate, decode(p.c_endorsement_code, null, nvl(to_char(lcc.start_date, ‘yyyy-mm-dd‘), to_char(p.start_date, ‘yyyy-mm-dd‘)), to_char(ipt.start_date, ‘yyyy-mm-dd‘)) as starDate, decode(p.c_endorsement_code, null, nvl(to_char(lcc.end_date, ‘yyyy-mm-dd‘), to_char(p.end_date, ‘yyyy-mm-dd‘)), to_char(ipt.end_date, ‘yyyy-mm-dd‘)) as endDate, to_char(p.d_ddate, ‘yyyy-mm-dd‘) as ddate, decode(se.c_paid_id, null, ‘否‘, ‘是‘) as selletStatus, se.C_PAYMENT_CODE as settlementCode, p.c_is_paid as isSettled, p.C_PERIOD as periodno, p.C_INSURANCE_ID as insuranceId, nvl(p.c_insurant_name, lcc.customer_name) as insuredName from paid_info_target p, lccont_target lcc, d_projects d, prem_payment_detail_target se, insurance_policy_target ipt where p.c_unite_policy = lcc.contno(+) and p.c_project_code = d.project_code(+) and p.C_PAID_ID = se.C_PAID_ID(+) and (p.c_unite_policy = ipt.contno(+) and p.c_endorsement_code = ipt.mli_insurance_endorsement_no(+)) and p.C_INSURANCE_COM_CODE = ‘0001300049.00158‘ and p.c_dept_id = ‘JT015200107‘ and p.c_branch_code = ‘JT0152001‘ and p.c_system_name like ‘%‘ || ‘旅游保险网‘ || ‘%‘ order by lcc.INSURANCE_POLICY_NO desc) t1, import_pay_confirm t2 where t2.c_bath_no = 1 and t1.endorsenentCode = t2.C_ENDORSEMENT_CODE and t2.c_import_by = ‘dx.xie‘ and t2.c_policy_no is null and t2.c_apply_no is null union all select distinct t1.* from (select p.c_paid_id as id, p.c_branch_name as organName, p.c_dept_name as daptName, d.project_name as itemName, p.c_Insurance_Com_Name as pryerName, nvl(p.n_Current_Premium, 0) as commission, decode(p.c_Endorsement_Code, null, ‘保单‘, ‘批单‘) as policyType, p.c_Apply_Code as allInsuranceCode, nvl(p.c_insurance_code, lcc.INSURANCE_POLICY_NO) as insuranceCode, p.c_Endorsement_Code as endorsenentCode, decode(p.c_endorsement_code, null, nvl(to_char(lcc.sign_time, ‘yyyy-mm-dd‘), to_char(p.sign_time, ‘yyyy-mm-dd‘)), to_char(ipt.effective_date, ‘yyyy-mm-dd‘)) as signDate, decode(p.c_endorsement_code, null, nvl(to_char(lcc.start_date, ‘yyyy-mm-dd‘), to_char(p.start_date, ‘yyyy-mm-dd‘)), to_char(ipt.start_date, ‘yyyy-mm-dd‘)) as starDate, decode(p.c_endorsement_code, null, nvl(to_char(lcc.end_date, ‘yyyy-mm-dd‘), to_char(p.end_date, ‘yyyy-mm-dd‘)), to_char(ipt.end_date, ‘yyyy-mm-dd‘)) as endDate, to_char(p.d_ddate, ‘yyyy-mm-dd‘) as ddate, decode(se.c_paid_id, null, ‘否‘, ‘是‘) as selletStatus, se.C_PAYMENT_CODE as settlementCode, p.c_is_paid as isSettled, p.C_PERIOD as periodno, p.C_INSURANCE_ID as insuranceId, nvl(p.c_insurant_name, lcc.customer_name) as insuredName from paid_info_target p, lccont_target lcc, d_projects d, prem_payment_detail_target se, insurance_policy_target ipt where p.c_unite_policy = lcc.contno(+) and p.c_project_code = d.project_code(+) and p.C_PAID_ID = se.C_PAID_ID(+) and (p.c_unite_policy = ipt.contno(+) and p.c_endorsement_code = ipt.mli_insurance_endorsement_no(+)) and p.C_INSURANCE_COM_CODE = 0001300049.00158 and p.c_dept_id = ‘JT015200107‘ and p.c_branch_code = ‘JT0152001‘ and p.c_system_name like ‘%‘ || ‘旅游保险网‘ || ‘%‘ order by lcc.INSURANCE_POLICY_NO desc) t1, import_pay_confirm t2 where t2.c_bath_no = 1 and t1.insuranceId = t2.C_INSURANCE_ID and t2.c_import_by = ‘dx.xie‘ and t2.c_policy_no is null and t2.c_apply_no is null and t2.C_ENDORSEMENT_CODE is null); PLAN_TABLE_OUTPUT -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- SQL_ID 8stbf7dskgqcy, child number 0 ------------------------------------- Plan hash value: 3629687165 -------------------------------------------------------------------------------------------------------------------------------------------------------- | Id | Operation | Name | Starts | E-Rows | A-Rows | A-Time | Buffers | OMem | 1Mem | Used-Mem | -------------------------------------------------------------------------------------------------------------------------------------------------------- | 0 | SELECT STATEMENT | | 1 | | 1 |00:00:00.03 | 3697 | | | | | 1 | SORT AGGREGATE | | 1 | 1 | 1 |00:00:00.03 | 3697 | | | | | 2 | VIEW | | 1 | 5 | 165 |00:00:00.03 | 3697 | | | | | 3 | UNION-ALL | | 1 | | 165 |00:00:00.03 | 3697 | | | | | 4 | HASH UNIQUE | | 1 | 1 | 165 |00:00:00.02 | 2942 | 698K| 698K| 1207K (0)| | 5 | NESTED LOOPS OUTER | | 1 | 1 | 165 |00:00:00.02 | 2942 | | | | | 6 | NESTED LOOPS OUTER | | 1 | 1 | 165 |00:00:00.01 | 2445 | | | | | 7 | NESTED LOOPS OUTER | | 1 | 1 | 165 |00:00:00.01 | 2441 | | | | | 8 | NESTED LOOPS OUTER | | 1 | 1 | 165 |00:00:00.01 | 1954 | | | | | 9 | NESTED LOOPS | | 1 | 1 | 165 |00:00:00.01 | 1622 | | | | |* 10 | TABLE ACCESS FULL | IMPORT_PAY_CONFIRM | 1 | 145 | 164 |00:00:00.01 | 374 | | | | |* 11 | TABLE ACCESS BY INDEX ROWID| PAID_INFO_TARGET | 164 | 1 | 165 |00:00:00.01 | 1248 | | | | |* 12 | INDEX RANGE SCAN | INDEX_PAID_5 | 164 | 1 | 990 |00:00:00.01 | 496 | | | | | 13 | TABLE ACCESS BY INDEX ROWID | D_PROJECTS | 165 | 1 | 165 |00:00:00.01 | 332 | | | | |* 14 | INDEX RANGE SCAN | INDEX_D_PROJECTS_1 | 165 | 1 | 165 |00:00:00.01 | 167 | | | | | 15 | TABLE ACCESS BY INDEX ROWID | LCCONT_TARGET | 165 | 1 | 153 |00:00:00.01 | 487 | | | | |* 16 | INDEX RANGE SCAN | INDEX_LCCONT_CONTNO | 165 | 1 | 153 |00:00:00.01 | 334 | | | | |* 17 | TABLE ACCESS BY INDEX ROWID | INSURANCE_POLICY_TARGET | 165 | 1 | 1 |00:00:00.01 | 4 | | | | |* 18 | INDEX RANGE SCAN | INDEX_INSUE_POLICY_1 | 165 | 1 | 1 |00:00:00.01 | 3 | | | | | 19 | TABLE ACCESS BY INDEX ROWID | PREM_PAYMENT_DETAIL_TARGET | 165 | 1 | 165 |00:00:00.01 | 497 | | | | |* 20 | INDEX RANGE SCAN | INDEX_PREM_DETAIL_1 | 165 | 1 | 165 |00:00:00.01 | 332 | | | | | 21 | HASH UNIQUE | | 1 | 1 | 0 |00:00:00.01 | 374 | 687K| 687K| | | 22 | NESTED LOOPS OUTER | | 1 | 1 | 0 |00:00:00.01 | 374 | | | | | 23 | NESTED LOOPS OUTER | | 1 | 1 | 0 |00:00:00.01 | 374 | | | | | 24 | NESTED LOOPS OUTER | | 1 | 1 | 0 |00:00:00.01 | 374 | | | | | 25 | NESTED LOOPS OUTER | | 1 | 1 | 0 |00:00:00.01 | 374 | | | | | 26 | NESTED LOOPS | | 1 | 1 | 0 |00:00:00.01 | 374 | | | | |* 27 | TABLE ACCESS FULL | IMPORT_PAY_CONFIRM | 1 | 7 | 0 |00:00:00.01 | 374 | | | | |* 28 | TABLE ACCESS BY INDEX ROWID| PAID_INFO_TARGET | 0 | 1 | 0 |00:00:00.01 | 0 | | | | |* 29 | INDEX RANGE SCAN | INDEX_POLICYNO | 0 | 1 | 0 |00:00:00.01 | 0 | | | | | 30 | TABLE ACCESS BY INDEX ROWID | D_PROJECTS | 0 | 1 | 0 |00:00:00.01 | 0 | | | | |* 31 | INDEX RANGE SCAN | INDEX_D_PROJECTS_1 | 0 | 1 | 0 |00:00:00.01 | 0 | | | | |* 32 | TABLE ACCESS BY INDEX ROWID | INSURANCE_POLICY_TARGET | 0 | 1 | 0 |00:00:00.01 | 0 | | | | |* 33 | INDEX RANGE SCAN | INDEX_INSUE_POLICY_1 | 0 | 1 | 0 |00:00:00.01 | 0 | | | | | 34 | TABLE ACCESS BY INDEX ROWID | PREM_PAYMENT_DETAIL_TARGET | 0 | 1 | 0 |00:00:00.01 | 0 | | | | |* 35 | INDEX RANGE SCAN | INDEX_PREM_DETAIL_1 | 0 | 1 | 0 |00:00:00.01 | 0 | | | | | 36 | TABLE ACCESS BY INDEX ROWID | LCCONT_TARGET | 0 | 1 | 0 |00:00:00.01 | 0 | | | | |* 37 | INDEX RANGE SCAN | INDEX_LCCONT_CONTNO | 0 | 1 | 0 |00:00:00.01 | 0 | | | | | 38 | HASH UNIQUE | | 1 | 1 | 0 |00:00:00.01 | 374 | 687K| 687K| | | 39 | NESTED LOOPS OUTER | | 1 | 1 | 0 |00:00:00.01 | 374 | | | | | 40 | NESTED LOOPS OUTER | | 1 | 1 | 0 |00:00:00.01 | 374 | | | | | 41 | NESTED LOOPS OUTER | | 1 | 1 | 0 |00:00:00.01 | 374 | | | | | 42 | NESTED LOOPS | | 1 | 1 | 0 |00:00:00.01 | 374 | | | | | 43 | NESTED LOOPS | | 1 | 8 | 0 |00:00:00.01 | 374 | | | | |* 44 | TABLE ACCESS FULL | IMPORT_PAY_CONFIRM | 1 | 7 | 0 |00:00:00.01 | 374 | | | | | 45 | TABLE ACCESS BY INDEX ROWID| LCCONT_TARGET | 0 | 1 | 0 |00:00:00.01 | 0 | | | | |* 46 | INDEX RANGE SCAN | INDEX_LCCONT_INSURANCE_PNO | 0 | 1 | 0 |00:00:00.01 | 0 | | | | |* 47 | TABLE ACCESS BY INDEX ROWID | PAID_INFO_TARGET | 0 | 1 | 0 |00:00:00.01 | 0 | | | | |* 48 | INDEX RANGE SCAN | INDEX_PAID_1 | 0 | 1 | 0 |00:00:00.01 | 0 | | | | | 49 | TABLE ACCESS BY INDEX ROWID | D_PROJECTS | 0 | 1 | 0 |00:00:00.01 | 0 | | | | |* 50 | INDEX RANGE SCAN | INDEX_D_PROJECTS_1 | 0 | 1 | 0 |00:00:00.01 | 0 | | | | |* 51 | TABLE ACCESS BY INDEX ROWID | INSURANCE_POLICY_TARGET | 0 | 1 | 0 |00:00:00.01 | 0 | | | | |* 52 | INDEX RANGE SCAN | INDEX_INSUE_POLICY_1 | 0 | 1 | 0 |00:00:00.01 | 0 | | | | | 53 | TABLE ACCESS BY INDEX ROWID | PREM_PAYMENT_DETAIL_TARGET | 0 | 1 | 0 |00:00:00.01 | 0 | | | | |* 54 | INDEX RANGE SCAN | INDEX_PREM_DETAIL_1 | 0 | 1 | 0 |00:00:00.01 | 0 | | | | | 55 | HASH UNIQUE | | 1 | 1 | 0 |00:00:00.01 | 3 | 687K| 687K| | | 56 | NESTED LOOPS OUTER | | 1 | 1 | 0 |00:00:00.01 | 3 | | | | | 57 | NESTED LOOPS OUTER | | 1 | 1 | 0 |00:00:00.01 | 3 | | | | | 58 | NESTED LOOPS OUTER | | 1 | 1 | 0 |00:00:00.01 | 3 | | | | | 59 | NESTED LOOPS OUTER | | 1 | 1 | 0 |00:00:00.01 | 3 | | | | | 60 | NESTED LOOPS | | 1 | 1 | 0 |00:00:00.01 | 3 | | | | |* 61 | TABLE ACCESS BY INDEX ROWID| IMPORT_PAY_CONFIRM | 1 | 1 | 0 |00:00:00.01 | 3 | | | | |* 62 | INDEX FULL SCAN | INDEX_NAME2 | 1 | 4 | 4 |00:00:00.01 | 1 | | | | |* 63 | TABLE ACCESS BY INDEX ROWID| PAID_INFO_TARGET | 0 | 1 | 0 |00:00:00.01 | 0 | | | | |* 64 | INDEX RANGE SCAN | INDEX_PAID_2 | 0 | 655 | 0 |00:00:00.01 | 0 | | | | | 65 | TABLE ACCESS BY INDEX ROWID | D_PROJECTS | 0 | 1 | 0 |00:00:00.01 | 0 | | | | |* 66 | INDEX RANGE SCAN | INDEX_D_PROJECTS_1 | 0 | 1 | 0 |00:00:00.01 | 0 | | | | | 67 | TABLE ACCESS BY INDEX ROWID | LCCONT_TARGET | 0 | 1 | 0 |00:00:00.01 | 0 | | | | |* 68 | INDEX RANGE SCAN | INDEX_LCCONT_CONTNO | 0 | 1 | 0 |00:00:00.01 | 0 | | | | |* 69 | TABLE ACCESS BY INDEX ROWID | INSURANCE_POLICY_TARGET | 0 | 1 | 0 |00:00:00.01 | 0 | | | | |* 70 | INDEX RANGE SCAN | INDEX_INSUE_POLICY_1 | 0 | 1 | 0 |00:00:00.01 | 0 | | | | | 71 | TABLE ACCESS BY INDEX ROWID | PREM_PAYMENT_DETAIL_TARGET | 0 | 1 | 0 |00:00:00.01 | 0 | | | | |* 72 | INDEX RANGE SCAN | INDEX_PREM_DETAIL_1 | 0 | 1 | 0 |00:00:00.01 | 0 | | | | | 73 | HASH UNIQUE | | 1 | 1 | 0 |00:00:00.01 | 4 | 687K| 687K| | | 74 | NESTED LOOPS OUTER | | 1 | 1 | 0 |00:00:00.01 | 4 | | | | | 75 | NESTED LOOPS OUTER | | 1 | 1 | 0 |00:00:00.01 | 4 | | | | | 76 | NESTED LOOPS OUTER | | 1 | 1 | 0 |00:00:00.01 | 4 | | | | | 77 | NESTED LOOPS OUTER | | 1 | 1 | 0 |00:00:00.01 | 4 | | | | | 78 | NESTED LOOPS | | 1 | 1 | 0 |00:00:00.01 | 4 | | | | |* 79 | TABLE ACCESS BY INDEX ROWID| IMPORT_PAY_CONFIRM | 1 | 1 | 0 |00:00:00.01 | 4 | | | | |* 80 | INDEX FULL SCAN | INDEX_NAME4 | 1 | 60 | 60 |00:00:00.01 | 3 | | | | |* 81 | TABLE ACCESS BY INDEX ROWID| PAID_INFO_TARGET | 0 | 1 | 0 |00:00:00.01 | 0 | | | | |* 82 | INDEX RANGE SCAN | INDEX_PAID_4 | 0 | 1 | 0 |00:00:00.01 | 0 | | | | | 83 | TABLE ACCESS BY INDEX ROWID | D_PROJECTS | 0 | 1 | 0 |00:00:00.01 | 0 | | | | |* 84 | INDEX RANGE SCAN | INDEX_D_PROJECTS_1 | 0 | 1 | 0 |00:00:00.01 | 0 | | | | |* 85 | TABLE ACCESS BY INDEX ROWID | INSURANCE_POLICY_TARGET | 0 | 1 | 0 |00:00:00.01 | 0 | | | | |* 86 | INDEX RANGE SCAN | INDEX_INSUE_POLICY_1 | 0 | 1 | 0 |00:00:00.01 | 0 | | | | | 87 | TABLE ACCESS BY INDEX ROWID | PREM_PAYMENT_DETAIL_TARGET | 0 | 1 | 0 |00:00:00.01 | 0 | | | | |* 88 | INDEX RANGE SCAN | INDEX_PREM_DETAIL_1 | 0 | 1 | 0 |00:00:00.01 | 0 | | | | | 89 | TABLE ACCESS BY INDEX ROWID | LCCONT_TARGET | 0 | 1 | 0 |00:00:00.01 | 0 | | | | |* 90 | INDEX RANGE SCAN | INDEX_LCCONT_CONTNO | 0 | 1 | 0 |00:00:00.01 | 0 | | | | -------------------------------------------------------------------------------------------------------------------------------------------------------- Predicate Information (identified by operation id): --------------------------------------------------- 10 - filter(("T2"."C_IMPORT_BY"=‘dx.xie‘ AND "T2"."C_APPLY_NO" IS NOT NULL AND "T2"."C_BATH_NO"=1)) 11 - filter(("P"."C_INSURANCE_COM_CODE"=‘0001300049.00158‘ AND "P"."C_DEPT_ID"=‘JT015200107‘ AND "P"."C_BRANCH_CODE"=‘JT0152001‘ AND "P"."C_SYSTEM_NAME" LIKE ‘%旅游保险网%‘ AND "P"."C_SYSTEM_NAME" IS NOT NULL)) 12 - access("P"."C_APPLY_CODE"="T2"."C_APPLY_NO") 14 - access("P"."C_PROJECT_CODE"="D"."PROJECT_CODE") 16 - access("P"."C_UNITE_POLICY"="LCC"."CONTNO") 17 - filter("P"."C_UNITE_POLICY"="IPT"."CONTNO") 18 - access("P"."C_ENDORSEMENT_CODE"="IPT"."MLI_INSURANCE_ENDORSEMENT_NO") 20 - access("P"."C_PAID_ID"="SE"."C_PAID_ID") 27 - filter(("T2"."C_APPLY_NO" IS NULL AND "T2"."C_POLICY_NO" IS NOT NULL AND "T2"."C_IMPORT_BY"=‘dx.xie‘ AND "T2"."C_BATH_NO"=1)) 28 - filter(("P"."C_INSURANCE_COM_CODE"=‘0001300049.00158‘ AND "P"."C_DEPT_ID"=‘JT015200107‘ AND "P"."C_BRANCH_CODE"=‘JT0152001‘ AND "P"."C_SYSTEM_NAME" LIKE ‘%旅游保险网%‘ AND "P"."C_SYSTEM_NAME" IS NOT NULL)) 29 - access("P"."C_INSURANCE_CODE"="T2"."C_POLICY_NO") filter("P"."C_INSURANCE_CODE" IS NOT NULL) 31 - access("P"."C_PROJECT_CODE"="D"."PROJECT_CODE") 32 - filter("P"."C_UNITE_POLICY"="IPT"."CONTNO") 33 - access("P"."C_ENDORSEMENT_CODE"="IPT"."MLI_INSURANCE_ENDORSEMENT_NO") 35 - access("P"."C_PAID_ID"="SE"."C_PAID_ID") 37 - access("P"."C_UNITE_POLICY"="LCC"."CONTNO") 44 - filter(("T2"."C_APPLY_NO" IS NULL AND "T2"."C_POLICY_NO" IS NOT NULL AND "T2"."C_IMPORT_BY"=‘dx.xie‘ AND "T2"."C_BATH_NO"=1)) 46 - access("LCC"."INSURANCE_POLICY_NO"="T2"."C_POLICY_NO") 47 - filter(("P"."C_INSURANCE_CODE" IS NULL AND "P"."C_INSURANCE_COM_CODE"=‘0001300049.00158‘ AND "P"."C_DEPT_ID"=‘JT015200107‘ AND "P"."C_BRANCH_CODE"=‘JT0152001‘ AND "P"."C_SYSTEM_NAME" LIKE ‘%旅游保险网%‘ AND "P"."C_SYSTEM_NAME" IS NOT NULL)) 48 - access("P"."C_UNITE_POLICY"="LCC"."CONTNO") 50 - access("P"."C_PROJECT_CODE"="D"."PROJECT_CODE") 51 - filter("P"."C_UNITE_POLICY"="IPT"."CONTNO") 52 - access("P"."C_ENDORSEMENT_CODE"="IPT"."MLI_INSURANCE_ENDORSEMENT_NO") 54 - access("P"."C_PAID_ID"="SE"."C_PAID_ID") 61 - filter(("T2"."C_APPLY_NO" IS NULL AND "T2"."C_IMPORT_BY"=‘dx.xie‘ AND "T2"."C_POLICY_NO" IS NULL AND "T2"."C_BATH_NO"=1)) 62 - filter("T2"."C_ENDORSEMENT_CODE" IS NOT NULL) 63 - filter(("P"."C_INSURANCE_COM_CODE"=‘0001300049.00158‘ AND "P"."C_DEPT_ID"=‘JT015200107‘ AND "P"."C_BRANCH_CODE"=‘JT0152001‘ AND "P"."C_SYSTEM_NAME" LIKE ‘%旅游保险网%‘ AND "P"."C_SYSTEM_NAME" IS NOT NULL)) 64 - access("P"."C_ENDORSEMENT_CODE"="T2"."C_ENDORSEMENT_CODE") filter("P"."C_ENDORSEMENT_CODE" IS NOT NULL) 66 - access("P"."C_PROJECT_CODE"="D"."PROJECT_CODE") 68 - access("P"."C_UNITE_POLICY"="LCC"."CONTNO") 69 - filter("P"."C_UNITE_POLICY"="IPT"."CONTNO") 70 - access("P"."C_ENDORSEMENT_CODE"="IPT"."MLI_INSURANCE_ENDORSEMENT_NO") 72 - access("P"."C_PAID_ID"="SE"."C_PAID_ID") 79 - filter(("T2"."C_APPLY_NO" IS NULL AND "T2"."C_IMPORT_BY"=‘dx.xie‘ AND "T2"."C_POLICY_NO" IS NULL AND "T2"."C_ENDORSEMENT_CODE" IS NULL AND "T2"."C_BATH_NO"=1)) 80 - filter("T2"."C_INSURANCE_ID" IS NOT NULL) 81 - filter(("P"."C_DEPT_ID"=‘JT015200107‘ AND "P"."C_BRANCH_CODE"=‘JT0152001‘ AND "P"."C_SYSTEM_NAME" LIKE ‘%旅游保险网%‘ AND TO_NUMBER("P"."C_INSURANCE_COM_CODE")=1300049.00158 AND "P"."C_SYSTEM_NAME" IS NOT NULL)) 82 - access("P"."C_INSURANCE_ID"="T2"."C_INSURANCE_ID") 84 - access("P"."C_PROJECT_CODE"="D"."PROJECT_CODE") 85 - filter("P"."C_UNITE_POLICY"="IPT"."CONTNO") 86 - access("P"."C_ENDORSEMENT_CODE"="IPT"."MLI_INSURANCE_ENDORSEMENT_NO") 88 - access("P"."C_PAID_ID"="SE"."C_PAID_ID") 90 - access("P"."C_UNITE_POLICY"="LCC"."CONTNO") 163 rows selected.
对buffer的消耗从之前的142K降到现在的3697，下降了97%多。我没有对优化的逻辑进行详细描述，虽然最后处理不太复杂，但是分析问题的过程事实上相当繁琐与复杂，曾经一度陷入中断，但是改写后的SQL的逻辑其实很简单，执行时间大概在0.1秒左右。
这段大的SQL其实还有优化空间，但是手头上的事情太多了，我准备继续对其进行优化，但不是现在，我相信这也是很多同行们的共同处境。
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原文地址：http://www.cnblogs.com/libisheng-20160828/p/5962074.html
