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Wiki / Locks

SHARE

Conflicts with the ROW EXCLUSIVE, SHARE UPDATE EXCLUSIVE, SHARE ROW EXCLUSIVE, EXCLUSIVE, and ACCESS EXCLUSIVE lock modes. This mode protects a table against concurrent data changes. Acquired by CREATE INDEX (without CONCURRENTLY).

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Compatibility

Compare different transactions holding locks on the same Table lock.

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Commands acquiring this mode

SQL commandObject, phase and conditions
CREATE INDEX (without CONCURRENTLY)Lock the indexed table, preventing concurrent writes. Source
REINDEX (parent table)Ordinary REINDEX takes SHARE on the table and ACCESS EXCLUSIVE on the index itself. The index lock is not an ACCESS EXCLUSIVE lock on the whole table. Source
LOCK TABLE … IN SHARE MODERequest this table mode explicitly. Omitting IN MODE defaults to ACCESS EXCLUSIVE. Source

Other lock modes

conflicts
row-exclusive, share-update-exclusive, share-row-exclusive, exclusive, access-exclusive
summary
Conflicts with the ROW EXCLUSIVE, SHARE UPDATE EXCLUSIVE, SHARE ROW EXCLUSIVE, EXCLUSIVE, and ACCESS EXCLUSIVE lock modes. This mode protects a table against concurrent data changes.

Definition PG 18

Conflicts with the ROW EXCLUSIVE, SHARE UPDATE EXCLUSIVE, SHARE ROW EXCLUSIVE, EXCLUSIVE, and ACCESS EXCLUSIVE lock modes. This mode protects a table against concurrent data changes. Acquired by CREATE INDEX (without CONCURRENTLY).

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Complete source facts

commands

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provenance

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Source references

Full definition and evidence JSON

Definition sources

center · PostgreSQL 18 · wiki-repair-20261023:9be26abf3e3f6a9991a257c3808aaca8d971c39d8267944a82bd317dcc353c0e

Text language: en · wiki-repair-20261023:9be26abf3e3f6a9991a257c3808aaca8d971c39d8267944a82bd317dcc353c0e