Mysql???????輰???
???????????? ???????[ 2017/1/4 10:56:09 ] ????????MySQL ?????
????3. ???????? ????н???????????????????????????????????磬????????CHAR(255)???У???????10????20???????????????Ω?????????????????н??????????????????????????????????????????????I/O??????
????4. ?????????? MySQL??????????????????????where?????????????????????????order by?е???????????????????????????????????????????????2?????????????????????????????е????????????????Щ?д?????????????
????5. like?????? ???????2????????like?????????????ò????????????????????like “%aaa%” ?????????????like “aaa%”?????????????
????6. ???????????????? ???磺select * from users where YEAR(adddate)<2007???????????????????????????????Ч???????????裬?????????????select * from users where adddate<’2007-01-01′??????????????Χ??????????????????MYSQL?????????
???????????£?MySQL?????2????????????????<??<=??=??>??>=??between??in??????Щ????like(????????%??_?????????)???????????????????????16?????????????????????????????????????????????????????????????????????text???????δ??????????????????????
????????EXPLAIN?÷??? ??е??????????????????????????????????????????????????ο???????????????????????м????????????????????????????????????????????????????????????????????????е÷????--????????????????????е?????????????????1000???????????????????MySQL?????????????????????????????????????????塣
?????????????????Щ?????????????????????????EXPLAIN SELECT???????????????????Щ??????????????????????????SELECT????????EXPLAIN????????????????????????????MySQL??????????????SELECT????????????????з?????MySQL??????????????????й?????????????(????е??)??????г?????
??????EXPLAIN???????????????1??????????????????????????????????????????????С?type??????????????????????????????????(JOIN)?????????????????????У?Ч??????system???????????const??eq_ref??ref??range??index??All(All?????????????????????????????????????????????????м??????????????--????????????????????????????)??
????possible_keys?????и?????MySQL????????????????????????????key????????MySQL??????????????????????????????????key_len???????????????????????????INTEGER?????е???????????????????4?????????????????????key_len???????????????MySQL???????????????Щ???????????????key_len???????????С???(????????)??
????ref?????и???????????????????????????????е??????row????????MySQL?????????????????????????????????????е??????row????????????????????????????????????????????????????????
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????8.key??index????
????mysql??key??index?????е????????????????????????????????????
????1).key ????????????????????????????壬??????????????????淶???????????????????????????????????????????primary key?? unique key?? foreign key ???
????primary key ??????????????????????constraint?????????淶????洢?????????????????key??????????index??
????unique key ???????????????????????constraint?????淶??????????????????key??????????index??
????foreign key???????????????????????constraint?????淶??????????????????????????key??????????index??
?????????mysql??key????????constraint??index?????壬??????????????????????????????????oracle?????????????????????index??????????key??????????????
??????1??????μ???key????????? ?? create table t (id int not null primary key);
??????2????????constraint???????????create table t(id int?? CONSTRAINT pk_t_id PRIMARY key (id));
??????3????????key???????????create table t(id int?? primary key (id));
????????key??????????????????????????????constraint?????????index???????index?????????constraint??key??
????2).index????????????????????????????????????????????????mysql?е?innodb???????????????????洢?????????????????????????????????????
???????????????????????????????????????ε??????????key????????飩??
?????磬create table t(id int?? index inx_tx_id (id));
????3).????????
????(1).???????????????????????????????????????(?????????index)???????????????index??????key??
???????? create table t(id int?? unique index inx_tx_id (id)); --index??????key???
????(2).?????????????????????????index??????index???????????key??????key????????????????????????á?
???????????????????????漰???????????????????SPASVOС??(021-61079698-8054)?????????????????????????
??????
?????????????????????????Щ????????????????????TC???????????????Щ???????????????????????????????????????????????(java .net ?????)???mysql???????????????????ж????д???Python???????????????(DB2)??????BufferPool????????????????????????????????6??????????????????滮???????????????-????????SQL Server???????????????????λ?????PHP??SQL????????????????????Pythonд???NoSQL????????? SQL ?е????????????? SQL ?е?????????Java???????:?????MySQL???????
???·???
??????????????????
2023/3/23 14:23:39???д?ò??????????
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2021/9/17 15:19:29???·???????·
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2021/5/28 17:25:47??????APP??????????
2021/5/8 17:01:11????????
?????????App Bug???????????????????????Jmeter?????????QC??????APP????????????????app?????е????????jenkins+testng+ant+webdriver??????????????JMeter????HTTP???????Selenium 2.0 WebDriver ??????