小编Arc*_*uke的帖子

我终于问了我的第一个问题(虽然我是一个长期跟踪者).

SQL查询在前几天引起了我的注意.WHERE当使用INoperator 将索引与可能的值进行比较时,问题是performance in 子句.

SELECT   SUM (parts.quantity) AS quantity,
       concessions.concessionCode,
       concessions.description AS concessionDesc,
       parts.type,
       activities.activityCode,
       REPLACE (activities.activityCode, activities.lvl2 || '-', '') AS activityCodeDisplay,
       strings.activityDesc,
       strings.activityDesc2,
       strings.activityDesc3
FROM   tb_parts parts,
       tb_activities activities,
       tb_strings strings,
       tb_concessions concessions
WHERE       parts.activityCode = activities.activityCode
       AND parts.concessionCode = activities.concessionCode
       AND activities.concessionCode = concesions.concessionCode
       AND activities.concessionCode = strings.concessionCode
       AND activities.activityCode = strings.activityCode
       AND strings.language = 'ENG'
       --AND parts.concesionCode IN ('ZD', 'G9', 'TR', 'JS0')
       AND parts.concesionCode IN ('ZD', 'G9')
       AND parts.date >= TO_DATE …