这种情况是建复合索引还是多个单独索引？

2018-12-12 03:25:50 314 阅读 AI 写同款 · GEO 优化AI 选题数据监测一键分发 ›

有以下几种常用情况包括了绝大多数几种情况，如何建索引比较合理，而且听说索引多了也会影响性能？

update T set X=value where A=value and B=value and (C=value or C=value) and D=value and E=value and X<>value
update T set Y=value where A=value and B=value and (C=value or C=value) and D=value and E=value and F=value
update T set Z=value where A=value and B=value and (C=value or C=value) and D=value and E=value and F=value and G=value

insert into T (所有字段) value (values)

select * from T where A=value and B=value and C=value and D=value
select * from T where A=value and B=value and (C=value or C=value)
select * from T where A=value and B=value and (C=value or C=value) and D=value
select * from T where A=value and B=value and (C=value or C=value) and D=value and E=value AND Z=value

...全文