pg_settings

Use this reference to list every Firebolt engine setting, its current value, and its default using the Postgres-compatible pg_catalog.pg_settings view.

Nightly Feature

You can use the pg_catalog.pg_settings view to list every setting the engine defines, together with its current value, its default, its type, and its description. Firebolt provides it for compatibility with Postgres clients and tools that read pg_settings to discover engine configuration.

SELECT
  *
FROM
  pg_catalog.pg_settings;

Most of these settings are internal settings. Their names and defaults change between releases, and some exist only to gate work in progress. Read them to understand what an engine is doing, but do not build on them. The public settings, meaning the ones Firebolt documents, supports, and keeps stable, are listed in System settings, and information_schema.settings reports that set with these same columns.

SHOW ALL is a three-column projection of this view, so it covers the same settings.

The setting column holds the value in effect for the query that reads the view, so a value changed with SET earlier in the session is reflected there, while boot_val and reset_val keep reporting the default.

Any setting this view reports can also be read one at a time, by name, with current_setting:

SELECT
  current_setting('max_result_rows');

Custom settings, meaning names the engine does not define, are not listed, and current_setting does not read them either.

Columns

Each row describes one setting. Columns that Firebolt does not populate are always NULL; they exist so that Postgres clients find the shape they expect.

Column Name	Data Type	Description
name	TEXT	Name of the setting.
setting	TEXT	Current value of the setting, as text.
unit	TEXT	Always NULL.
category	TEXT	Always NULL.
short_desc	TEXT	Description of the setting.
extra_desc	TEXT	Always NULL.
context	TEXT	Always user. Every listed setting can be changed for a session or a single query.
vartype	TEXT	SQL type of the setting value: boolean, bigint, real, or text. A setting that only accepts a fixed set of names reports enum, and enumvals lists those names.
source	TEXT	Always NULL.
min_val	TEXT	Always NULL.
max_val	TEXT	Always NULL.
enumvals	ARRAY(TEXT)	Every value a setting with vartype enum accepts, in the order the engine declares them. NULL for all other settings. A few settings accept any comma-separated combination of the listed values rather than exactly one of them; their description says so.
boot_val	TEXT	Default value of the setting, as text.
reset_val	TEXT	Default value of the setting, as text.
sourcefile	TEXT	Always NULL.
sourceline	INTEGER	Always NULL.
pending_restart	BOOLEAN	Always false. Settings take effect immediately.

Example

Look up specific settings and compare their current values against the defaults:

SELECT
  name,
  setting,
  boot_val,
  vartype
FROM
  pg_catalog.pg_settings
WHERE
  name IN ('enable_result_cache', 'insert_sharding', 'max_result_rows')
ORDER BY
  name;

name	setting	boot_val	vartype
enable_result_cache	true	true	boolean
insert_sharding	auto	auto	enum
max_result_rows	0	0	bigint

A name that returns a row here but no row from information_schema.settings is an internal setting, so treat it as an implementation detail rather than an interface.