ALTER SYSTEM — change a server configuration parameter
ALTER SYSTEM SETconfiguration_parameter
{ TO | = } {value
| 'value
' | DEFAULT } ALTER SYSTEM RESETconfiguration_parameter
ALTER SYSTEM RESET ALL
ALTER SYSTEM is used for changing server configuration
parameters across the entire database cluster. It can be more convenient
than the traditional method of manually editing
the postgresql.conf
file.
ALTER SYSTEM writes the given parameter setting to
the postgresql.auto.conf
file, which is read in
addition to postgresql.conf
.
Setting a parameter to DEFAULT
, or using the
RESET variant, removes that configuration entry from the
postgresql.auto.conf
file. Use RESET
ALL
to remove all such configuration entries.
Values set with ALTER SYSTEM will be effective after
the next server configuration reload (SIGHUP
or pg_ctl reload
), or after the next server restart in the
case of parameters that can only be changed at server start.
Only superusers can use ALTER SYSTEM. Also, since this command acts directly on the file system and cannot be rolled back, it is not allowed inside a transaction block or function.
configuration_parameter
Name of a settable configuration parameter. Available parameters are documented in Chapter 18, Server Configuration.
value
New value of the parameter. Values can be specified as string
constants, identifiers, numbers, or comma-separated lists of
these, as appropriate for the particular parameter.
DEFAULT
can be written to specify removing the
parameter and its value from postgresql.auto.conf
.
This command can't be used to set data_directory,
nor parameters that are not allowed in postgresql.conf
(e.g., preset options).
See the section called “Setting Parameters” for other ways to set the parameters.