SELECT [ ALL | DISTINCT [ ON ( expression [, ...] ) ] ]
* | expression [ AS output_name ] [, ...]
INTO [ TEMPORARY | TEMP ] [ TABLE ] new_table
[ FROM from_item [, ...] ]
[ WHERE condition ]
[ GROUP BY expression [, ...] ]
[ HAVING condition [, ...] ]
[ { UNION | INTERSECT | EXCEPT } [ ALL ] select ]
[ ORDER BY expression [ ASC | DESC | USING operator ] [, ...] ]
[ LIMIT { count | ALL } ]
[ OFFSET start ]
[ FOR UPDATE [ OF tablename [, ...] ] ]
If specified, the table is created as a temporary table. Refer to CREATE TABLE for details.
The name (optionally schema-qualified) of the table to be created.
All other inputs are described in detail for SELECT.
SELECT INTO creates a new table and fills it with data computed by a query. The data is not returned to the client, as it is with a normal SELECT. The new table's columns have the names and data types associated with the output columns of the SELECT.
Note: CREATE TABLE AS is functionally equivalent to SELECT INTO. CREATE TABLE AS is the recommended syntax, since SELECT INTO is not standard. In fact, this form of SELECT INTO is not available in PL/pgSQL or ecpg, because they interpret the INTO clause differently.
SQL92 uses SELECT ... INTO to represent selecting values into scalar variables of a host program, rather than creating a new table. This indeed is the usage found in PL/pgSQL and ecpg. The PostgreSQL usage of SELECT INTO to represent table creation is historical. It's best to use CREATE TABLE AS for this purpose in new code. (CREATE TABLE AS isn't standard either, but it's less likely to cause confusion.)