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????????????????????????user???username??password??age????????????????????Σ?????????????У????????????????????(????????????????????????)????person_info??profile??????ó?????????????н??д洢????????????????????????????????????????????????
?????????
????1.????mysql??????????????д????
????????????1.master??????????????????????????binlog??????????????????????????Щ????????????????У?2.??slave?????????????????master???????????????????м?????У????м?????ж?????μ??????????????????????????
???????????mysql????????????????MysqlProxy????????https://segmentfault.com/a/11...
????sql?????????? ??????????????
??????Σ????????????????????????ε?????????? ???????δ??? select *
????????????sql????????????д?????????????????????????????????????????????????????????????????????????????????????????????????????????????￡?age????????sex ??ε????
?????????????????????з????????????150??????????10000??????????????????????? where id > 1500000 limit 150??д?????? limit 10000??150 .??????????????????????
????????????????????????limit 1??????mysql??????????????????????????????????????????
????????????????????????select ... from t1 where t1.uid IN (select uid from t2 )??????????????select ... from t1 where exists(select 1 from t2 where t2.uid=t1.id).??????????????????????е????????????????????????????????
???????????????????????sql????д???????????sql??????
????????????????????????????????ε??????varchar???????дwhere?????????where name='11' ??? where name=11?????????????????????int?????3????????????