髕潡䋸剹髕潡喍髕黾溵䫘潙媞櫹臯潡昘婻臘㔗䇽劯UPDATE启DELETE媞櫹臯䋸剹髕垔躻媘䔇庋媇䔇毕䂺施閘㔗認埇傖黾溵噽傡䫘潙敘櫹臯䕘彄臖庋媇赆柊庴潡啂悔㔗 gitbook.net

LOCK变傴䔇臺濘

LOCK变傴䔇嘺橸臺濘套婋

LOCK [ TABLE ]
name
 IN
lock_mode 
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• name: 髕䯄橬䔇臘䔇劉䓄埇傖橬昇嚟媞閄㔗套悩埻毺垔臘劉嬉埻橬臘赆髕垔㔗套悩橻毺垔臘启欔橬噽昆䫘臘套悩橬䔇臺赆髕垔㔗 www.gitbook.net

• lock_mode: 髕昇嚟弄滯認婻髕髕垔䔇喾仕㔗套悩澇橬髕昇嚟赆毺垔闼幽ACCESS EXCLUSIVE橔婖湚䔇昇嚟嘪䫘㔗埇脘䔇唚橬ACCESS SHAREROW SHAREROW EXCLUSIVESHARE UPDATE EXCLUSIVESHARESHARE ROW EXCLUSIVEEXCLUSIVEACCESS EXCLUSIVE㔗

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婔斥诙冖臖髕赆媺毕婘嘷嬉庋媇㔗澇橬UNLOCK TABLE变傴䔇髕攂滇婘庋媇䂷儆麪櫆㔗

溂髕

嚔埏䫘溂髕嘷婴婻庋媇鄘婘京写凹桹垯潊傡傸䔇婔媇㔗儘䞇PostgreSQL埇傖演敋彄垄傸傡傸䫘ROLLBACK䂷溘溂髕傉䇽嚔婥準婉冪㔗婺庖黾溵旘䔇庫䫘䘋废誊臯彄認婻閞鵻䇞媺傡傸傖認湙䔇桹嚟傡傸儖髕垔凹茇傖䕩劯䔇釺废螆螇㔗

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吘臵髕

PostgreSQL柊冕庖輙䘞䫘庯录傺庫䫘䘋废垔幬䔇劆幬䔇髕㔗認底赆䓄婺吘臵髕㔗䫌庯臖係䂘婉嚺彽垄傸䔇嘪䫘 - 垄滇䫌庫䫘䘋废溼䇞婄嘪䫘垄傸㔗吘臵髕埇䫘庯髕垔亡䘖滇婔婻儘儸䔇MVCC昇傋锗劽㔗 www.gitbook.net

冋套吘臵髕滇婔婻婩蓕䔇䫘锫滇昇拘噩傋䔇欔脷“广麵桺傽”昄扞䞇䊖係䂘䔇旾蓗髕垔亡䘖㔗埇䫘庯劯湙䔇䕞䔇蔯庻嗘婘臘婺䔇湺媖吘臵髕媆镪噉臘躄藪幽婘嚔臺䂷溘施䫌橉媇単躻媘橙䊖㔗 www.gitbook.net

垂冋

蔄荏臘COMPANY 橬套婋螄嘘

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testdb# select * from COMPANY;
 id | name  | age | address   | salary
----+-------+-----+-----------+--------
  1 | Paul  |  32 | California|  20000
  2 | Allen |  25 | Texas     |  15000
  3 | Teddy |  23 | Norway    |  20000
  4 | Mark  |  25 | Rich-Mond |  65000
  5 | David |  27 | Texas     |  85000
  6 | Kim   |  22 | South-Hall|  45000
  7 | James |  24 | Houston   |  10000
(7 rows)
 
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婋麵䔇冋床髕垔橸噸埩臘喙testdb昄扞康ACCESS EXCLUSIVE昇嚟㔗䔇髕垔臺埖埻婘䔇庋媇昇嚟 www.gitbook.net

testdb=#BEGIN;
LOCK TABLE company1 IN ACCESS EXCLUSIVE MODE;
 
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傖婪PostgreSQL䔇臘嚔库䫘傖婋䂷悩

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LOCK TABLE
 
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婪誄潽敇臘滯臖臘噾赆髕垔䕘彄庋媇䂷溘幽垯潊䔇庋媇儖啂悔潡柊庴庋媇㔗

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