pg_settings

The view pg_settings provides access to run-time parameters of the server. It is essentially an alternative interface to the SHOW and SET commands. It also provides access to some facts about each parameter that are not directly available from SHOW, such as minimum and maximum values.

Name	Type	References	Description
name	text		run-time configuration parameter name
setting	text		current value of the parameter
category	text		logical group of the parameter
short_desc	text		a brief description of the parameter
extra_desc	text		additional, more detailed, information about the parameter
context	text		context required to set the parameter's value
vartype	text		parameter type (bool, integer, real, or string)
source	text		source of the current parameter value
min_val	text		minimum allowed value of the parameter (NULL for nonnumeric values)
max_val	text		maximum allowed value of the parameter (NULL for nonnumeric values)

The pg_settings view cannot be inserted into or deleted from, but it can be updated. An UPDATE applied to a row of pg_settings is equivalent to executing the SET command on that named parameter. The change only affects the value used by the current session. If an UPDATE is issued within a transaction that is later aborted, the effects of the UPDATE command disappear when the transaction is rolled back. Once the surrounding transaction is committed, the effects will persist until the end of the session, unless overridden by another UPDATE or SET.