Getting Information About Databases and Tables

When you create a table, PostgreSQL stores the definition of that table in the system catalog. The system catalog is a collection of PostgreSQL tables. You can issue SELECT statements against the system catalog tables just like any other table, but there are easier ways to view table and index definitions.

When you are using the psql client application, you can view the list of tables defined in your database using the \d meta-command:

 movies=# \d             List of relations        Name        Type       Owner ------------------+-------+---------------  customers         table  bruce  distributors      table  bruce  rentals           table  bruce  returns           table  John Whorfin  tapes             table  bruce 

To see the detailed definition of a particular table, use the \d table-name meta-command:

 movies=# \d tapes                 Table "tapes"  Column           Type           Modifiers ---------+-----------------------+-----------  tape_id  character(8)           not null  title    character varying(80)   dist_id  integer                Primary key: tapes_pkey Triggers: RI_ConstraintTrigger_74939,           RI_ConstraintTrigger_74941,           RI_ConstraintTrigger_74953 

You can also view a list of all indexes defined in your database. The \di meta-command displays indexes:

 movies=# \di                 List of relations            Name             Type       Owner ---------------------------+-------+--------------- customers_pkey              index  Administrator distributors_pkey           index  Administrator tapes_pkey                  index  Administrator 

You can see the full definition for any given index using the \d index-name meta-command:

 movies=# \d tapes    Index "tapes_pkey"  Column       Type ---------+--------------  tape_id  character(8) unique btree (primary key) 

Table 3.1 shows a complete list of the system catalog- related meta-commands in psql :

Table 3.1. System Catalog Meta-Commands

Command	Result
\d \dt	List all tables
\di	List all indexes
\ds	List all sequences
\dv	List all views
\dS	List all PostgreSQL-defined tables
\d table-name	Show table definition
\d index-name	Show index definition
\d view-name	Show view definition
\d sequence-name	Show sequence definition
\dp	List all privileges
\dl	List all large objects
\da	List all aggregates
\df	List all functions
\df function-name	List all functions with given name
\do	List all operators
\do operator-name	List all operators with given name
\dT	List all types
\l	List all databases in this cluster

Alternative Views (Oracle-Style Dictionary Views)

One of the nice things about an open -source product is that code contributions come from many different places. One such project exists to add Oracle-style dictionary views to PostgreSQL. If you are an experienced Oracle user , you will appreciate this feature. The orapgsqlviews project contributes Oracle-style views such as all_views , all_tables , user_tables , and so on. For more information, see http://gborg.postgresql.org.