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.