default_table_access_method — PostgreSQL configuration parameter

This parameter specifies the default table access method to use when creating tables or materialized views if the CREATE command does not explicitly specify an access method, or when SELECT …

At a glance

What it does

This parameter specifies the default table access method to use when creating tables or materialized views if the CREATE command does not explicitly specify an access method, or when SELECT … INTO is used, which does not allow specifying a table access method. The default is heap.

(Description quoted from the official PostgreSQL documentation.)

How to apply a change

Can be set per session with SET, per role/database with ALTER ROLE/DATABASE ... SET, or globally in postgresql.conf.

Inspect the current value and source with SHOW default_table_access_method; or SELECT name, setting, unit, context, source FROM pg_settings WHERE name = 'default_table_access_method';.

Tuning guidance

This sets a session default (locale, formatting, search path or transaction behaviour) rather than a performance knob. Set it per role or database with ALTER ROLE/DATABASE ... SET so the right default follows the right workload, and prefer setting it explicitly in the application for behaviour the query results depend on.

Reference

PostgreSQL documentation — default_table_access_method.