(FAQ)总账凭证基本信息查询，系统不响应，导致EAS Cloud系统整体性能慢

(FAQ)总账凭证基本信息查询，系统不响应，导致EAS Cloud系统整体性能慢
原因分析： 1.查询的sql语句中存在影响性能的distinct。Distinct 对sql结果集中所有的记录先进行排序，然后对重复的记录进行筛选。最后对重复的记录分别选出一条与原本不重复的记录一并显示出来。排序与筛选过程非常耗资源。 2.缺少必要的where条件。缺少必要的where条件，导致基表数据量大，与其它表走netsted loop连接耗用较多的cpu资源。由于nested loop连接是基表与附表的所有记录一一进行连接，发现附表有相等的记录后，返回相等的记录。如果基表数据量较大的话，与附表关连的次数较多，影响查询速度。 在OEM中抓取到对应的语句如下所示： INSERT INTO VTZI8JRL51QD152GWCQSTI6FN5D (KSQL_SEQ, ID, ENTRIESID) SELECT ROWNUM, KSQL_V1.* FROM (SELECT TMP_SUBSELECT_ALIAS."ID", TMP_SUBSELECT_ALIAS."ENTRIES.ID" FROM (SELECT * FROM (SELECT DISTINCT "VOUCHER".FID "ID","ENTRIES".FID "ENTRIES.ID", "VOUCHER".FNumber "NUMBER", "ENTRIES".FSeq "ENTRIES.SEQ" FROM T_GL_Voucher "VOUCHER" LEFT OUTER JOIN T_BD_Period "PERIOD" ON "VOUCHER".FPeriodID = "PERIOD".FID INNER JOIN T_ORG_Company "COMPANY" ON "VOUCHER".FCompanyID ="COMPANY".FID INNER JOIN T_GL_VoucherEntry "ENTRIES" ON "VOUCHER".FID = "ENTRIES".FBillID INNER JOIN T_BD_VoucherTypes "VOUCHERTYPE" ON "VOUCHER".FVoucherTypeID = "VOUCHERTYPE".FID INNER JOIN T_PM_User "CREATOR" ON "VOUCHER".FCreatorID = "CREATOR".FID INNER JOIN (SELECT DISTINCT "VOUCHER".FID "ID" FROM T_GL_Voucher "VOUCHER" LEFT OUTER JOIN T_BD_Period "PERIOD" ON "VOUCHER".FPeriodID ="PERIOD"