CREATE TABLE ... AS Statement (ANSI Valid-Time Table Form) | Teradata Vantage - CREATE TABLE ... AS (ANSI Valid-Time Table Form) - Advanced SQL Engine - Teradata Database

Purpose

Creates a new temporal table by copying all or a portion of the structure and contents of an existing temporal table.

Syntax

There is no special additional temporal syntax for the CREATE TABLE ... AS statement. The syntax is identical to that used for nontemporal tables. That syntax is described fully in Teradata Vantage™ - SQL Data Definition Language Syntax and Examples, B035-1144. But note the restrictions listed in the Usage Notes below.

Usage Notes for ANSI Valid-Time Tables

• In order to copy the derived VALIDTIME period definition to the new table, you must use the table-copy form: CREATE TABLE target_table AS source_table rather than CREATE TABLE target_table AS (subquery).
• If you specify new column names in the table-copy form of a CREATE TABLE AS statement, you must specify a name for the valid-time derived period column, which is also copied from the source valid-time table.
• You cannot, and need not, explicitly specify the [AS] VALIDTIME column attribute in a CREATE TABLE AS statement, even if you specify new column names for the target table.
• If WITH DATA is specified in the CREATE TABLE ... AS statement, the valid-time column values are copied to the target table.
• Target tables can be created with column- and table-level temporal constraints. For valid-time tables having primary key and unique constraints, the database automatically creates system-defined join indexes (SJIs). These types of constraints can be defined on target tables in CREATE TABLE ... AS statements only if the WITH NO DATA option is used. (Note that NONSEQUENCED VALIDTIME primary key and unique constraints act as for nontemporal tables, and create unique secondary indexes, rather than SJIs.)