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 32 ) 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 43-35 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 25-1 .
Except where noted, all the views described here are read-only.
Table 43-35. System Views
|pg_group||groups of database users|
|pg_locks||currently held locks|
|pg_timezone_abbrevs||time zone abbreviations|
|pg_timezone_names||time zone names|