Wiki / Configuration Parameters

The shared lock table has space for max_locks_per_transaction objects (e.g., tables) per server process or prepared transaction; hence, no more than this many distinct objects can be locked at any one time. This parameter limits the average number of object locks used by each transaction; individual transactions can lock more objects as long as the locks of all transactions fit in the lock table. This is not the number of rows that can be locked; that value is unlimited. The default, 64, has historically proven sufficient, but you might need to raise this value if you have queries that touch many different tables in a single transaction, e.g., query of a parent table with many children. This parameter can only be set at server start. When running a standby server, you must set this parameter to have the same or higher value as on the primary server. Otherwise, queries will not be allowed in the standby server.

English manual coverage begins with PostgreSQL 7.4. Source history and runtime observations have their own recorded version boundaries.

boot val

64

category

Lock Management

context

postmaster

documented

true

enumvals

Unknown

extra desc

The shared lock table is sized on the assumption that at most "max_locks_per_transaction" objects per server process or prepared transaction will need to be locked at any one time.

lang

en

max val

2147483647

metadata version

18

min val

10

name

max_locks_per_transaction

short desc

Sets the maximum number of locks per transaction.

source

pg-settings-source-snapshot

unit

Unknown

vartype

integer