PostgreSQL 8.0.1 Documentation
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CREATE TABLE AS

Name

CREATE TABLE AS -- define a new table from the results of a query

Synopsis

CREATE [ [ GLOBAL | LOCAL ] { TEMPORARY | TEMP } ] TABLE table_name [ (column_name [, ...] ) ] [ [ WITH | WITHOUT ] OIDS ] AS query

Description

CREATE TABLE AS creates a table and fills it with data computed by a SELECT command or an EXECUTE that runs a prepared SELECT command. The table columns have the names and data types associated with the output columns of the SELECT (except that you can override the column names by giving an explicit list of new column names).

CREATE TABLE AS bears some resemblance to creating a view, but it is really quite different: it creates a new table and evaluates the query just once to fill the new table initially. The new table will not track subsequent changes to the source tables of the query. In contrast, a view re-evaluates its defining SELECT statement whenever it is queried.

Parameters

GLOBAL or LOCAL: Ignored for compatibility. Refer to CREATE TABLE for details.

TEMPORARY or TEMP: If specified, the table is created as a temporary table. Refer to CREATE TABLE for details.
table_name: The name (optionally schema-qualified) of the table to be created.
column_name: The name of a column in the new table. If column names are not provided, they are taken from the output column names of the query. If the table is created from an EXECUTE command, a column name list cannot be specified.
WITH OIDS WITHOUT OIDS: This optional clause specifies whether the table created by CREATE TABLE AS should include OIDs. If neither form of this clause is specified, the value of the default_with_oids configuration parameter is used.
query: A query statement (that is, a SELECT command or an EXECUTE command that runs a prepared SELECT command). Refer to SELECT or EXECUTE, respectively, for a description of the allowed syntax.

Notes

This command is functionally similar to SELECT INTO, but it is preferred since it is less likely to be confused with other uses of the SELECT INTO syntax. Furthermore, CREATE TABLE AS offers a superset of the functionality offered by SELECT INTO.

Prior to PostgreSQL 8.0, CREATE TABLE AS always included OIDs in the table it produced. As of PostgresSQL 8.0, the CREATE TABLE AS command allows the user to explicitly specify whether OIDs should be included. If the presence of OIDs is not explicitly specified, the default_with_oids configuration variable is used. While this variable currently defaults to true, the default value may be changed in the future. Therefore, applications that require OIDs in the table created by CREATE TABLE AS should explicitly specify WITH OIDS to ensure compatibility with future versions of PostgreSQL.

Examples

Create a new table films_recent consisting of only recent entries from the table films:

CREATE TABLE films_recent AS SELECT * FROM films WHERE date_prod >= '2002-01-01';

Compatibility

CREATE TABLE AS is specified by the SQL:2003 standard. There are some small differences between the definition of the command in SQL:2003 and its implementation in PostgreSQL:

The standard requires parentheses around the subquery clause; in PostgreSQL, these parentheses are optional.
The standard defines an ON COMMIT clause; this is not currently implemented by PostgreSQL.
The standard defines a WITH DATA clause; this is not currently implemented by PostgreSQL.