CREATE TABLE AS

Defines a new table from the results of a query.

Synopsis

CREATE [ [ GLOBAL | LOCAL ] { TEMPORARY | TEMP } | UNLOGGED ] TABLE [ IF NOT EXISTS ] <table_name>
        [ (<column_name> [, ...] ) ]
        [ USING <access_method> ]
        [ WITH ( <storage_parameter> [= <value>] [, ... ] ) | WITHOUT OIDS ]
        [ ON COMMIT { PRESERVE ROWS | DELETE ROWS | DROP } ]
        [ TABLESPACE <tablespace_name> ]
        AS <query>
        [ WITH [ NO ] DATA ]
        [ DISTRIBUTED BY ( <column> [<opclass>] [, ... ] ) 
           | DISTRIBUTED RANDOMLY
           | DISTRIBUTED REPLICATED ]

Description

CREATE TABLE AS creates a table and fills it with data computed by a SELECT command. The table columns have the names and data types associated with the output columns of the SELECT, however you can override the column names by giving an explicit list of new column names.

CREATE TABLE AS 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.

Parameters

GLOBAL | LOCAL

Ignored for compatibility. These keywords are deprecated; refer to CREATE TABLE for details.

TEMPORARY | TEMP

If specified, the new table is created as a temporary table. Refer to CREATE TABLE for details.

UNLOGGED

If specified, the table is created as an unlogged table. Refer to CREATE TABLE for details.

IF NOT EXISTS

Do not throw an error if a relation with the same name already exists; simply issue a notice and leave the table unmodified.

table_name

The name (optionally schema-qualified) of the new 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.

USING access_method

The optional USING clause specifies the table access method to use to store the contents for the new table you are creating; the method must be an access method of type TABLE. Set to heap to access the table as a heap-storage table, ao_row to access the table as an append-optimized table with row-oriented storage (AO), or ao_column to access the table as an append-optimized table with column-oriented storage (AO/CO). The default access method is determined by the value of the default_table_access_method server configuration parameter.

Note:

Although you can specify the table's access method using WITH (appendoptimized=true|false, orientation=row|column). We recommend that you use USING <access_method> instead.

WITH ( storage_parameter=value )

The WITH clause specifies optional storage parameters for the new table. Refer to the Storage Parameters section on the CREATE TABLE reference page for more information.

ON COMMIT

The behavior of temporary tables at the end of a transaction block can be controlled using ON COMMIT. The three options are:

PRESERVE ROWS — Cloudberry Database takes no special action at the ends of transactions for temporary tables. This is the default behavior.

DELETE ROWS — Cloudberry Database deletes all rows in the temporary table at the end of each transaction block. Essentially, an automatic TRUNCATE is done at each commit.

DROP — Cloudberry Database drops the temporary table at the end of the current transaction block.

TABLESPACE tablespace_name

The tablespace_name parameter is the name of the tablespace in which the new table is to be created. If not specified, the database's default_tablespace is used, or temp_tablespaces if the table is temporary.

AS query

A SELECT, TABLE, or VALUES command, or an EXECUTE command that runs a prepared SELECT, TABLE, or VALUES query.

DISTRIBUTED BY ( column [opclass] [, ... ] )
DISTRIBUTED RANDOMLY
DISTRIBUTED REPLICATED

Used to declare the Cloudberry Database distribution policy for the table. Refer to CREATE TABLE for details.

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.

CREATE TABLE AS can be used for fast data loading from external table data sources. See CREATE EXTERNAL TABLE.

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 >= '2020-01-01';

To copy a table completely, you can also use the short form by specifying the TABLE command:

CREATE TABLE films2 AS
  TABLE films;

Create a new temporary table films_recent, consisting only of recent entries from the table films, using a prepared statement. The new table will be dropped at commit:

PREPARE recentfilms(date) AS
  SELECT * FROM films WHERE date_prod > $1;
CREATE TEMP TABLE films_recent ON COMMIT DROP AS 
  EXECUTE recentfilms('2020-01-01');

Compatibility

CREATE TABLE AS conforms to the SQL standard, with the following exceptions:

• The standard requires parentheses around the subquery clause; in Cloudberry Database, these parentheses are optional.
• In the standard, the WITH [NO] DATA clause is required, in Cloudberry Database it is optional.
• Cloudberry Database handles temporary tables differently from the standard; see CREATE TABLE for details.
• The WITH clause is a Cloudberry Database extension; storage parameters are not part of the standard.
• The Cloudberry Database concept of tablespaces is not part of the standard. The TABLESPACE clause is an extension.

See also

CREATE EXTERNAL TABLE, CREATE MATERIALIZED VIEW, CREATE TABLE, EXECUTE, SELECT, SELECT INTO, VALUES