Provided by: postgres-xc-client_1.1-2ubuntu2_amd64 
NAME
CREATE_TABLE_AS - define a new table from the results of a query
SYNOPSIS
CREATE [ [ GLOBAL | LOCAL ] { TEMPORARY | TEMP } | UNLOGGED ] TABLE table_name
[ (column_name [, ...] ) ]
[ WITH ( storage_parameter [= value] [, ... ] ) | WITH OIDS | WITHOUT OIDS ]
[ ON COMMIT { PRESERVE ROWS | DELETE ROWS | DROP } ]
[ TABLESPACE tablespace_name ]
[ DISTRIBUTE BY { REPLICATION | ROUNDROBIN | { [HASH | MODULO ] ( column_name ) } } ]
[ TO { GROUP groupname | NODE ( nodename [, ... ] ) } ]
AS query
[ WITH [ NO ] DATA ]
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 (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. Use of these keywords is deprecated; refer to CREATE TABLE
(CREATE_TABLE(7)) for details.
TEMPORARY or TEMP
If specified, the table is created as a temporary table. Refer to CREATE TABLE (CREATE_TABLE(7)) for
details.
UNLOGGED
If specified, the table is created as an unlogged table. Refer to CREATE TABLE (CREATE_TABLE(7)) 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.
WITH ( storage_parameter [= value] [, ... ] )
This clause specifies optional storage parameters for the new table; see Storage Parameters for more
information. The WITH clause can also include OIDS=TRUE (or just OIDS) to specify that rows of the
new table should have OIDs (object identifiers) assigned to them, or OIDS=FALSE to specify that the
rows should not have OIDs. See CREATE TABLE (CREATE_TABLE(7)) for more information.
WITH OIDS, WITHOUT OIDS
These are obsolescent syntaxes equivalent to WITH (OIDS) and WITH (OIDS=FALSE), respectively. If you
wish to give both an OIDS setting and storage parameters, you must use the WITH ( ... ) syntax; see
above.
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
No special action is taken at the ends of transactions. This is the default behavior.
DELETE ROWS
All rows in the temporary table will be deleted at the end of each transaction block.
Essentially, an automatic TRUNCATE(7) is done at each commit.
DROP
The temporary table will be dropped at the end of the current transaction block.
TABLESPACE tablespace_name
The tablespace_name is the name of the tablespace in which the new table is to be created. If not
specified, default_tablespace is consulted, or temp_tablespaces if the table is temporary.
DISTRIBUTE BY
Note
The following description applies only to Postgres-XC
This clause specifies how the table is distributed or replicated among Datanodes.
REPLICATION
Each row of the table will be replicated into all the Datanode of the Postgres-XC database
cluster.
ROUNDROBIN
Each row of the table will be placed in one of the Datanodes by round-robin manner. The value of
the row will not be needed to determine what Datanode to go.
HASH ( column_name )
Each row of the table will be placed based on the hash value of the specified column. Following
type is allowed as distribution column: INT8, INT2, OID, INT4, BOOL, INT2VECTOR, OIDVECTOR, CHAR,
NAME, TEXT, BPCHAR, BYTEA, VARCHAR, FLOAT4, FLOAT8, NUMERIC, CASH, ABSTIME, RELTIME, DATE, TIME,
TIMESTAMP, TIMESTAMPTZ, INTERVAL, and TIMETZ.
Please note that floating point is not allowed as a basis of the distribution column.
MODULO ( column_name )
Each row of the table will be placed based on the modulo of the specified column. Following type
is allowed as distribution column: INT8, INT2, OID, INT4, BOOL, INT2VECTOR, OIDVECTOR, CHAR,
NAME, TEXT, BPCHAR, BYTEA, VARCHAR, FLOAT4, FLOAT8, NUMERIC, CASH, ABSTIME, RELTIME, DATE, TIME,
TIMESTAMP, TIMESTAMPTZ, INTERVAL, and TIMETZ.
Please note that floating point is not allowed as a basis of the distribution column.
If DISTRIBUTE BY is not specified, columns with UNIQUE constraint will be chosen as the distribution
key. If no such column is specified, distribution column is the first eligible column in the
definition. If no such column is found, then the table will be distributed by ROUNDROBIN.
TO GROUP, TO NODE
This defines on the list of nodes on which table data exists. If this is not specified table data is
present on all Datanodes.
nodename
Associated with TO NODE, it defines a Postgres-XC node of catalog pgxc_node.
groupname
Associated with TO GROUP, it defines a Postgres-XC node group in catalog pgxc_group.
query
A SELECT(7), TABLE, or VALUES(7) command, or an EXECUTE(7) command that runs a prepared SELECT,
TABLE, or VALUES query.
WITH [ NO ] DATA
This clause specifies whether or not the data produced by the query should be copied into the new
table. If not, only the table structure is copied. The default is to copy the data.
NOTES
This command is functionally similar to SELECT INTO (SELECT_INTO(7)), 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.
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';
To copy a table completely, the short form using the TABLE command can also be used:
CREATE TABLE films2 AS
TABLE films;
Create a new temporary table films_recent, consisting of only recent entries from the table films, using
a prepared statement. The new table has OIDs and will be dropped at commit:
PREPARE recentfilms(date) AS
SELECT * FROM films WHERE date_prod > $1;
CREATE TEMP TABLE films_recent WITH (OIDS) ON COMMIT DROP AS
EXECUTE recentfilms('2002-01-01');
COMPATIBILITY
CREATE TABLE AS conforms to the SQL standard. The following are nonstandard extensions:
• The standard requires parentheses around the subquery clause; in Postgres-XC, these parentheses are
optional.
• In the standard, the WITH [ NO ] DATA clause is required; in Postgres-XC it is optional.
• Postgres-XC handles temporary tables in a way rather different from the standard; see CREATE TABLE
(CREATE_TABLE(7)) for details.
• The WITH clause is a PostgreSQL extension; neither storage parameters nor OIDs are in the standard.
• The Postgres-XC concept of tablespaces is not part of the standard. Hence, the clause TABLESPACE is
an extension.
SEE ALSO
CREATE TABLE (CREATE_TABLE(7)), EXECUTE(7), SELECT(7), SELECT INTO (SELECT_INTO(7)), VALUES(7)
Postgres-XC 1.1 2014-04-07 CREATE TABLE AS(7)