A great deal of data is stored in POSTGRESQL system tables. The names
of these tables begin with pg_. The tables contain information about
data types, functions , operators , databases,
users, and groups. Table shows the most commonly
used tables.
The pg_log table is a binary file rather than a real table. The pg_shadow table contains user passwords and is not visible to ordinary users. The pg_user table (not listed in Table ) is a view of pg_shadow that does not display the password field. Several other system views are available as well. Most system tables are joined using OIDs (see Section ). Psql's \dS command lists all system tables and views.