System Views

In addition to the system catalogs, PostgreSQL provides a number of built-in views. Some system views provide convenient access to some commonly used queries on the system catalogs. Other views provide access to internal server state.

The information schema ( Chapter 34 ) provides an alternative set of views which overlap the functionality of the system views. Since the information schema is SQL-standard whereas the views described here are PostgreSQL -specific, it's usually better to use the information schema if it provides all the information you need.

Table 48-55 lists the system views described here. More detailed documentation of each view follows below. There are some additional views that provide access to the results of the statistics collector; they are described in Table 27-1 .

Except where noted, all the views described here are read-only.

Table 48-55. System Views

View Name Purpose
pg_available_extensions available extensions
pg_available_extension_versions available versions of extensions
pg_cursors open cursors
pg_group groups of database users
pg_indexes indexes
pg_locks currently held locks
pg_matviews materialized views
pg_prepared_statements prepared statements
pg_prepared_xacts prepared transactions
pg_roles database roles
pg_rules rules
pg_seclabels security labels
pg_settings parameter settings
pg_shadow database users
pg_stats planner statistics
pg_tables tables
pg_timezone_abbrevs time zone abbreviations
pg_timezone_names time zone names
pg_user database users
pg_user_mappings user mappings
pg_views views