Wiki / 锁

ROW SHARE

Conflicts with the EXCLUSIVE and ACCESS EXCLUSIVE lock modes. The SELECT command acquires a lock of this mode on all tables on which one of the FOR UPDATE, FOR NO KEY UPDATE, FOR SHARE, or FOR KEY SHARE options is specified (in addition to ACCESS SHARE locks on any other tables that are referenced without any explicit FOR ... locking option).

当前阅读 PG 18·选择有来源记录的版本

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此版本暂无所选语言的定义，以下显示原始英文内容。

兼容性

比较不同事务持有同一对象的锁表锁.

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取得此锁模式的命令

SQL 命令	对象、阶段与条件
SELECT FOR KEY SHARE	Lock the named table, in addition to the corresponding locks on selected rows. 来源
SELECT FOR SHARE	Lock the named table, in addition to the corresponding locks on selected rows. 来源
SELECT FOR NO KEY UPDATE	Lock the named table, in addition to the corresponding locks on selected rows. 来源
SELECT FOR UPDATE	Lock the named table, in addition to the corresponding locks on selected rows. 来源
INSERT (foreign-key check)	The foreign-key check runs SELECT FOR KEY SHARE on the referenced table, taking ROW SHARE there. The writing target separately holds ROW EXCLUSIVE. 来源
UPDATE (foreign-key check)	The foreign-key check runs SELECT FOR KEY SHARE on the referenced table, taking ROW SHARE there. The writing target separately holds ROW EXCLUSIVE. 来源
COPY … FROM (foreign-key check)	The foreign-key check runs SELECT FOR KEY SHARE on the referenced table, taking ROW SHARE there. The writing target separately holds ROW EXCLUSIVE. 来源
MERGE (foreign-key check)	The foreign-key check runs SELECT FOR KEY SHARE on the referenced table, taking ROW SHARE there. The writing target separately holds ROW EXCLUSIVE. 来源
LOCK TABLE … IN ROW SHARE MODE	Request this table mode explicitly. Omitting IN MODE defaults to ACCESS EXCLUSIVE. 来源
ALTER TABLE … VALIDATE CONSTRAINT (referenced table)	Foreign-key validation takes ROW SHARE on the referenced table and SHARE UPDATE EXCLUSIVE on the table being validated. 来源

其他锁模式

conflicts: exclusive, access-exclusive
summary: Conflicts with the EXCLUSIVE and ACCESS EXCLUSIVE lock modes.

版本定义 PG 18

比较版本

完整来源事实

commands

map[label:SELECT FOR KEY SHARE note:Lock the named table, in addition to the corresponding locks on selected rows. slug:select source:map[kind:documentation path:doc/src/sgml/mvcc.sgml revision:753057e340da8f22e57c9a409ea7a235fd6a46bd sha256:4b7bf77ee0af4b86052330ff2421d567df3604b75fe7d4f522bec84fdea87340 url:https://raw.githubusercontent.com/postgres/postgres/753057e340da8f22e57c9a409ea7a235fd6a46bd/doc/src/sgml/mvcc.sgml] source_url:https://www.postgresql.org/docs/18/explicit-locking.html variant:0ecc8fb9e712], map[label:SELECT FOR SHARE note:Lock the named table, in addition to the corresponding locks on selected rows. slug:select source:map[kind:documentation path:doc/src/sgml/mvcc.sgml revision:753057e340da8f22e57c9a409ea7a235fd6a46bd sha256:4b7bf77ee0af4b86052330ff2421d567df3604b75fe7d4f522bec84fdea87340 url:https://raw.githubusercontent.com/postgres/postgres/753057e340da8f22e57c9a409ea7a235fd6a46bd/doc/src/sgml/mvcc.sgml] source_url:https://www.postgresql.org/docs/18/explicit-locking.html variant:8b3c78ad3c64], map[label:SELECT FOR NO KEY UPDATE note:Lock the named table, in addition to the corresponding locks on selected rows. slug:select source:map[kind:documentation path:doc/src/sgml/mvcc.sgml revision:753057e340da8f22e57c9a409ea7a235fd6a46bd sha256:4b7bf77ee0af4b86052330ff2421d567df3604b75fe7d4f522bec84fdea87340 url:https://raw.githubusercontent.com/postgres/postgres/753057e340da8f22e57c9a409ea7a235fd6a46bd/doc/src/sgml/mvcc.sgml] source_url:https://www.postgresql.org/docs/18/explicit-locking.html variant:dc13a30028da], map[label:SELECT FOR UPDATE note:Lock the named table, in addition to the corresponding locks on selected rows. slug:select source:map[kind:documentation path:doc/src/sgml/mvcc.sgml revision:753057e340da8f22e57c9a409ea7a235fd6a46bd sha256:4b7bf77ee0af4b86052330ff2421d567df3604b75fe7d4f522bec84fdea87340 url:https://raw.githubusercontent.com/postgres/postgres/753057e340da8f22e57c9a409ea7a235fd6a46bd/doc/src/sgml/mvcc.sgml] source_url:https://www.postgresql.org/docs/18/explicit-locking.html variant:9c457e2f8f3c], map[label:INSERT (foreign-key check) note:The foreign-key check runs SELECT FOR KEY SHARE on the referenced table, taking ROW SHARE there. The writing target separately holds ROW EXCLUSIVE. slug:insert source:map[kind:source path:src/backend/utils/adt/ri_triggers.c revision:753057e340da8f22e57c9a409ea7a235fd6a46bd sha256:a3fed49fbda88fe0fe5bcf35eb019fced28596ae4046233f2acb2eb9f90ab1da url:https://raw.githubusercontent.com/postgres/postgres/753057e340da8f22e57c9a409ea7a235fd6a46bd/src/backend/utils/adt/ri_triggers.c] source_url:https://github.com/postgres/postgres/blob/753057e340da8f22e57c9a409ea7a235fd6a46bd/src/backend/utils/adt/ri_triggers.c variant:ffddc0fc16b6], map[label:UPDATE (foreign-key check) note:The foreign-key check runs SELECT FOR KEY SHARE on the referenced table, taking ROW SHARE there. The writing target separately holds ROW EXCLUSIVE. slug:update source:map[kind:source path:src/backend/utils/adt/ri_triggers.c revision:753057e340da8f22e57c9a409ea7a235fd6a46bd sha256:a3fed49fbda88fe0fe5bcf35eb019fced28596ae4046233f2acb2eb9f90ab1da url:https://raw.githubusercontent.com/postgres/postgres/753057e340da8f22e57c9a409ea7a235fd6a46bd/src/backend/utils/adt/ri_triggers.c] source_url:https://github.com/postgres/postgres/blob/753057e340da8f22e57c9a409ea7a235fd6a46bd/src/backend/utils/adt/ri_triggers.c variant:65d8638ef74c], map[label:COPY … FROM (foreign-key check) note:The foreign-key check runs SELECT FOR KEY SHARE on the referenced table, taking ROW SHARE there. The writing target separately holds ROW EXCLUSIVE. slug:copy source:map[kind:source path:src/backend/utils/adt/ri_triggers.c revision:753057e340da8f22e57c9a409ea7a235fd6a46bd sha256:a3fed49fbda88fe0fe5bcf35eb019fced28596ae4046233f2acb2eb9f90ab1da url:https://raw.githubusercontent.com/postgres/postgres/753057e340da8f22e57c9a409ea7a235fd6a46bd/src/backend/utils/adt/ri_triggers.c] source_url:https://github.com/postgres/postgres/blob/753057e340da8f22e57c9a409ea7a235fd6a46bd/src/backend/utils/adt/ri_triggers.c variant:b85f269c1b8e], map[label:MERGE (foreign-key check) note:The foreign-key check runs SELECT FOR KEY SHARE on the referenced table, taking ROW SHARE there. The writing target separately holds ROW EXCLUSIVE. slug:merge source:map[kind:source path:src/backend/utils/adt/ri_triggers.c revision:753057e340da8f22e57c9a409ea7a235fd6a46bd sha256:a3fed49fbda88fe0fe5bcf35eb019fced28596ae4046233f2acb2eb9f90ab1da url:https://raw.githubusercontent.com/postgres/postgres/753057e340da8f22e57c9a409ea7a235fd6a46bd/src/backend/utils/adt/ri_triggers.c] source_url:https://github.com/postgres/postgres/blob/753057e340da8f22e57c9a409ea7a235fd6a46bd/src/backend/utils/adt/ri_triggers.c variant:e00dfdc184d6], map[label:LOCK TABLE … IN ROW SHARE MODE note:Request this table mode explicitly. Omitting IN MODE defaults to ACCESS EXCLUSIVE. slug:lock source:map[kind:documentation path:doc/src/sgml/mvcc.sgml revision:753057e340da8f22e57c9a409ea7a235fd6a46bd sha256:4b7bf77ee0af4b86052330ff2421d567df3604b75fe7d4f522bec84fdea87340 url:https://raw.githubusercontent.com/postgres/postgres/753057e340da8f22e57c9a409ea7a235fd6a46bd/doc/src/sgml/mvcc.sgml] source_url:https://www.postgresql.org/docs/18/explicit-locking.html variant:137512efd0b5], map[label:ALTER TABLE … VALIDATE CONSTRAINT (referenced table) note:Foreign-key validation takes ROW SHARE on the referenced table and SHARE UPDATE EXCLUSIVE on the table being validated. slug:alter-table source:map[kind:command-documentation path:doc/src/sgml/ref/alter_table.sgml revision:753057e340da8f22e57c9a409ea7a235fd6a46bd sha256:10436673fa2f093bdf51986a06d22dd748a9bb003bcd5517db2a65fba569a3c9 url:https://raw.githubusercontent.com/postgres/postgres/753057e340da8f22e57c9a409ea7a235fd6a46bd/doc/src/sgml/ref/alter_table.sgml] source_url:https://www.postgresql.org/docs/18/sql-altertable.html variant:f3ebdc754838]

provenance

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来源引用

完整定义与证据 JSON

定义来源

center · PostgreSQL 18 · 10:f4e8f137bfb08a664c8288824c1e36b5143ac875;11:170e416034ec0231d9e9238f2577eeb76ca8d181;12:3f302f0ed06f69c5ebd33d4df95895323a3cbef6;13:05f6c9ec2c475fae8fdd56ae40bd01afcf70d1f2;14:fba35c7c28a567839faba867db0808564c0a66db;15:0351991b8e7c7b64382e2f30ce581a8f276590a6;16:dcc37b7099a9f3cf2c75167d8dc92e75f96bc1fa;17:163288afd32a448244c8df75b3c33181aadd7f20;18:753057e340da8f22e57c9a409ea7a235fd6a46bd;19:b73d13c32c834a2c8e1c60cb92f79530376cedf1;20:2c10c2ce4d7bcd57543a49ab402af02a39724e0a

正文语言: en · 10:f4e8f137bfb08a664c8288824c1e36b5143ac875;11:170e416034ec0231d9e9238f2577eeb76ca8d181;12:3f302f0ed06f69c5ebd33d4df95895323a3cbef6;13:05f6c9ec2c475fae8fdd56ae40bd01afcf70d1f2;14:fba35c7c28a567839faba867db0808564c0a66db;15:0351991b8e7c7b64382e2f30ce581a8f276590a6;16:dcc37b7099a9f3cf2c75167d8dc92e75f96bc1fa;17:163288afd32a448244c8df75b3c33181aadd7f20;18:753057e340da8f22e57c9a409ea7a235fd6a46bd;19:b73d13c32c834a2c8e1c60cb92f79530376cedf1;20:2c10c2ce4d7bcd57543a49ab402af02a39724e0a