{"id":579,"date":"2010-08-24T13:25:00","date_gmt":"2010-08-24T05:25:00","guid":{"rendered":"http:\/\/note.systw.net\/note\/?p=579"},"modified":"2023-11-04T13:49:59","modified_gmt":"2023-11-04T05:49:59","slug":"transaction","status":"publish","type":"post","link":"https:\/\/systw.net\/note\/archives\/579","title":{"rendered":"Transaction"},"content":{"rendered":"\n

transaction<\/strong>
\u78ba\u4fdd\u591a\u500b\u52d5\u4f5c\u80fd\u4e00\u6b21\u5b8c\u6210<\/p>\n\n\n\n

\u4ea4\u932f\u57f7\u884c\u6642\u7684Concurrency(\u4e26\u884c),\u53ef\u80fd\u5c0e\u81f4\u7684\u554f\u984c\u6709<\/strong>
Lost Update Problem(\u907a\u5931\u66f4\u65b0\u554f\u984c)
Dirty Read Problem(\u4e0d\u6b63\u78ba\u8b80\u53d6\u554f\u984c)
The Incorrect Summary Problem(\u4e0d\u6b63\u78ba\u7684\u7e3d\u548c\u554f\u984c)<\/p>\n\n\n\n

\u4ea4\u6613\u7684ACID<\/strong>
Atomicity(\u55ae\u5143\u6027)
Consistency Preservation(\u4e00\u81f4\u6027\u7684\u4fdd\u7559)
Isolation(\u7368\u7acb\u6027)
Durability or Permanency(\u6c38\u4e45\u6027)<\/p>\n\n\n\n

\u53ef\u56de\u5fa9\u6027\u7684\u4ea4\u6613\u6392\u7a0b<\/strong>,\u6709\u4ee5\u4e0b\u5169\u7a2e
\u5faa\u5e8f\u6392\u7a0b
\u4ea4\u932f\u6392\u7a0b<\/p>\n\n\n\n

\u6392\u7a0b\u4e2d\u6703\u7522\u751f\u64cd\u4f5c\u885d\u7a81\u7684\u60c5\u6cc1<\/strong>
table1 read(x) -> table2 write(x)
table1 write(x) -> table2 read(x)
table1 write(x) -> table2 write(x)<\/p>\n\n\n\n

\u4ea4\u6613\u6392\u7a0b\u7684\u53ef\u5e8f\u5217\u6027<\/strong>,\u5206\u70ba
Serial(\u5e8f\u5217\u6027)
Non-Serial(\u975e\u5e8f\u5217\u6027)<\/p>\n\n\n\n

……………………….<\/p>\n\n\n\n

lock\u6280\u8853<\/strong>
lock level\u4f9d\u6700\u5927\u81f3\u6700\u5c0f\u5982\u4e0b
database level
table level
page level
row level
column level ex:sqlserver<\/p>\n\n\n\n

binary lock(\u4e8c\u5143\u9396\u5b9a)<\/strong>
\u6709lock\/unlock
\u907f\u514d\u5728\u66f4\u6539\u8cc7\u6599\u5c1a\u672b\u5b8c\u6210\u6642\u88ab\u5176\u4ed6\u66f4\u6539\u8cc7\u6599\u7684\u52d5\u4f5c\u5f71\u97ff
\u505a\u6cd5:\u5728\u66f4\u6539\u8cc7\u6599\u524d\u5148lock,\u66f4\u6539\u5b8c\u5f8c\u5728unlock,\u6b64\u6bb5\u6642\u9593\u5167\u7121\u6cd5\u88ab\u5916\u90e8\u66f4\u6539\u4e00\u76f4\u5230unlock\u5f8c
\u53ef\u80fd\u554f\u984c:\u56e0\u88ablock\u4f4f,\u800c\u5916\u90e8\u7121\u6cd5\u8b80\u8cc7\u6599<\/p>\n\n\n\n

share\/exclusive lock(\u5171\u4eab\/\u4e92\u65a5\u9396)<\/strong>
\u6709read lock\/write lock\/unlock
\u53ef\u89e3\u6c7a\u4e8c\u5143\u9396\u5b9a\u7684\u554f\u984c
\u53ef\u80fd\u554f\u984c:\u5e8f\u5217\u5316\u88ab\u6253\u65b7,\u6703\u4f7f\u8a18\u61b6\u9ad4\u672a\u66f4\u65b0,\u5c0e\u81f4\u6293\u53d6\u932f\u8aa4\u7684\u503c<\/p>\n\n\n\n

two phase lock(2\u968e\u6bb5\u9396\u5b9a)<\/strong>
\u53ef\u89e3\u6c7a\u5e8f\u5217\u5316\u88ab\u6253\u65b7
\u53ef\u80fd\u554f\u984c:\u5169\u908a\u82e5\u4f54\u8457\u8cc7\u6e90\u4e0d\u653e\u9020\u6210\u6b7b\u7d50<\/p>\n\n\n\n

\u6b7b\u7d50\u9810\u9632<\/strong>
2\u908a\u90fd\u88ablock\u6642,\u6709\u4ee5\u4e0b\u89e3\u6cd5
wait-die <\/strong>\u7b2c\u4e00\u500b\u5148wait\u8cc7\u6e90,\u4e4b\u5f8clock\u7684\u8981\u4e3b\u52d5\u91cb\u653e\u8cc7\u6e90,\u7b2c\u4e00\u500b\u5373\u53ef\u53d6\u5f97\u8cc7\u6e90
wound-wait<\/strong> \u7b2c\u4e00\u500block\u7684\u5f37\u5236\u5c07\u4e4b\u5f8clock\u7684\u91cb\u653e\u6389,\u7b2c\u4e00\u500b\u5373\u53ef\u53d6\u5f97\u8cc7\u6e90<\/p>\n\n\n\n

ps:
\u6b7b\u7d50\u9810\u9632:\u8981\u6c42\u7684\u8cc7\u6e90\u4e2d\u82e5\u6709\u5176\u4e2d\u4e00\u500b\u88ablock,\u5247\u91cb\u653e\u5168\u90e8\u8cc7\u6e90
\u6b7b\u7d50\u5075\u6e2c:\u5148\u5075\u6e2c\u6240\u9700\u7684\u8cc7\u6e90\u662f\u5426\u6709\u88ablock,\u82e5\u6709\u5247\u7b49\u6703\u5728\u505a
\u6b7b\u7d50\u907f\u514d:\u6240\u6709\u6240\u9700\u7684\u8cc7\u6e90\u90fd\u78ba\u5b9a\u88ab\u81ea\u5df1lock\u624d\u505a<\/p>\n\n\n\n

……………………………….<\/p>\n\n\n\n

MS SQL Server 2005\u7684<\/strong>transaction<\/strong>\u5206\u70ba\u5169\u7a2e<\/strong>
Implicit Transactions(\u96b1\u542b\u5f0f\u4ea4\u6613)
Explicit Transactions(\u660e\u78ba\u5f0f\u4ea4\u6613)<\/p>\n\n\n\n

\u96b1\u542b\u5f0f\u4ea4\u6613<\/strong>
\u64cd\u4f5c\u4e4b\u524d\uff1a\u9810\u8a2d\u5373\u70ba\u4ea4\u6613\u7684\u958b\u59cb\u72c0\u614b
\u56de\u5fa9\u5230\u64cd\u4f5c\u4e4b\u524d\uff1a\u6307\u4ee4ROLLBACK<\/strong>
\u6240\u6709\u64cd\u4f5c\u5b8c\u7562,\u4ea4\u6613\u7d50\u675f\uff1a\u6307\u4ee4COMMIT<\/strong>
ps
\u8a2d\u5b9a\u555f\u7528\u96b1\u542b\u5f0f\u4ea4\u6613
SET IMPLICIT_TRANSACTIONS ON<\/strong>
\u8a2d\u5b9a\u95dc\u9589\u96b1\u542b\u5f0f\u4ea4\u6613
SET IMPLICIT_TRANSACTIONS OFF<\/strong><\/p>\n\n\n\n

\u660e\u78ba\u5f0f\u4ea4\u6613<\/strong>
\u64cd\u4f5c\u4e4b\u524d\uff1a\u6307\u4ee4BEGIN TRANSACTION<\/strong>\u9032\u5165\u660e\u78ba\u5f0f\u4ea4\u6613
\u56de\u5fa9\u5230\u64cd\u4f5c\u4e4b\u524d\uff1a\u6307\u4ee4ROLLBACK<\/strong>
\u6240\u6709\u64cd\u4f5c\u5b8c\u7562,\u4ea4\u6613\u7d50\u675f\uff1a\u6307\u4ee4COMMIT<\/strong><\/p>\n\n\n\n

…….<\/p>\n\n\n\n

mysql\u4f7f\u7528transaction\u529f\u80fd<\/strong>
table\u985e\u578b\u70baInnoDB\u8207BDB
\u64cd\u4f5c\u4e4b\u524d\uff1a\u6307\u4ee4BEGIN<\/strong>
\u56de\u5fa9\u5230\u64cd\u4f5c\u4e4b\u524d\uff1a\u6307\u4ee4ROLLBACK<\/strong>
\u6240\u6709\u64cd\u4f5c\u5b8c\u7562,\u4ea4\u6613\u7d50\u675f\uff1a\u6307\u4ee4COMMIT<\/strong><\/p>\n\n\n\n

table\u985e\u578b\u70bamyisam
\u64cd\u4f5c\u4e4b\u524d\uff1a\u4f7f\u7528\u9396\u5b9a\u8a9e\u6cd5
LOCK TABLES tbl_name [AS alias] {READ [LOCAL] | [LOW_PRIORITY] WRITE}<\/strong>
\u6240\u6709\u64cd\u4f5c\u5b8c\u7562,\u4ea4\u6613\u7d50\u675f\uff1a\u89e3\u9664\u9396\u5b9a\u8a9e\u6cd5
UNLOCK TABLES;<\/strong><\/p>\n","protected":false},"excerpt":{"rendered":"

transaction\u78ba\u4fdd\u591a\u500b\u52d5\u4f5c\u80fd\u4e00\u6b21\u5b8c\u6210 \u4ea4\u932f\u57f7\u884c\u6642\u7684C …<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"fifu_image_url":"","fifu_image_alt":"","_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":false,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2}},"categories":[16],"tags":[],"class_list":["post-579","post","type-post","status-publish","format-standard","hentry","category-database"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/systw.net\/note\/wp-json\/wp\/v2\/posts\/579","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/systw.net\/note\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/systw.net\/note\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/systw.net\/note\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/systw.net\/note\/wp-json\/wp\/v2\/comments?post=579"}],"version-history":[{"count":0,"href":"https:\/\/systw.net\/note\/wp-json\/wp\/v2\/posts\/579\/revisions"}],"wp:attachment":[{"href":"https:\/\/systw.net\/note\/wp-json\/wp\/v2\/media?parent=579"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/systw.net\/note\/wp-json\/wp\/v2\/categories?post=579"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/systw.net\/note\/wp-json\/wp\/v2\/tags?post=579"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}