痛苦地缓慢DB2查询

Question

此查询非常缓慢,我们的团队无法弄清楚原因.我们尝试过创建视图,但它仍然非常慢.有什么想法吗？

SELECT 
    CI . CWARCASNBR AS CASENUMBER , 
    CI . CT1FYA AS COURTAGENCYCODE , 
    CI . CIPTYSQNBR AS PARTYSEQNBR , 
    CI . CIRCDTYPE AS CASETYPECODE , 
    CP . NMELASTBUS AS LASTNAME , 
    CP . NAME_FIRST AS FIRSTNAME , 
    CP . NAME_MID AS MIDDLENAME , 
    CP . NAME_SUFFX AS SUFFIX , 
    CP . CP_SEX AS GENDER , 
    CP . CT1PA AS RACECODE , 
    CP . CP_DOB AS DOB , 
    CP . CP_SSN AS SSN , 
    A . STREETNAME AS ADDRESS1 , 
    A . ADDRLINE2 AS ADDRESS2 , 
    A . CITYPARISH AS CITY , 
    A . ADDRSTATE AS STATE , 
    A . ZIPCODE AS ZIP 
FROM 
    CMSDPL23 . JE026001 AS CP 
  LEFT OUTER JOIN 
    CMSDPR23 . JE215000 CI ON 
    CP . JEBOA = CI . CWARCASNBR AND 
    CP . CT1FYA = CI . CT1FYA AND 
    CP . CP_SEQ_NBR = CI . CIPTYSQNBR 
  LEFT OUTER JOIN 
    CMSDPR23 . CT007000 A ON CP . ADDRESSID = A . ADDRESSID 
                         AND CP . ADDRESSPRI = A . ADDIDSEQNO 
WHERE 
    CP . NMELASTBUS LIKE 'Durham' || '%' AND 
    CP . NAME_FIRST LIKE 'Roger%' || '%' AND 
    NOT CP . PRTY_TCDE IN ( 'OFF' , 'BEP' ) AND 
    CI . CI_FLAG_1 IN ( 'C' , 'B' ) AND 
    CI . CT1MKA = '23' 
ORDER BY 
    CI . CWARCASNBR , CI . CT1FYA ; 

Answer 1

首先,所有外键关系都被编入索引吗？(例如,CMSDPR23.JE215000,CP.JEBOA等.

其次,LIKE强制进行全表搜索.你能索引NMELASTBUS和NAME_FIRST(等......)并检查匹配吗？

第三,您的WHERE子句中的字段是否已编入索引？