为什么我这条语句查询速度是30多秒啊?
SELECT a.filename,b.cn FROM a left join b on a.cn=b.cn where a.filename like 'mod-j2me%' and b.branch = 'shanxi_release' limit 10;
a表记录500000+,b表记录260000+,每天在增加。怎么办?
各位大侠,分不多,要多帮忙啊!
SELECT a.filename,b.cn FROM a left join b on a.cn=b.cn where a.filename like 'mod-j2me%' and b.branch = 'shanxi_release' limit 10;
a表记录500000+,b表记录260000+,每天在增加。怎么办?
各位大侠,分不多,要多帮忙啊!
alter table b add index(branch);
b:branch
left join b on a.cn=b.cn where a.filename like 'mod-j2me%' and b.branch = 'shanxi_release' limit 10;
分别filename和branch分别加索引。
left join b on a.cn=b.cn where a.filename like 'mod-j2me%' and b.branch = 'shanxi_release' limit 10;把表结构发下
执行一下
create index idx_cn_filename on a(cn,filename)
create index idx_cn_branch on a(cn,branch)看看
create index idx_cn_branch on b(cn,branch)