Teradata Vantage™ - Temporal Table Support describes syntax that is especially relevant to temporal tables. Syntax that is not required, or that is not otherwise specific to temporal tables is generally not shown in this document. For additional syntax, see
Teradata Vantage™ - SQL Data Definition Language Syntax and Examples, B035-1144 ,
Teradata Vantage™ - SQL Data Manipulation Language, B035-1146 , and
Teradata Vantage™ - SQL Data Control Language, B035-1149.
{ SET SESSION | SS }
{ valid_time_qualifier [ AND transaction_time_qualifier ] |
transaction_time_qualifier [ AND valid_time_qualifier ] |
AS OF date_timestamp_expression |
ANSIQUALIFIER
} [;]
- valid_time_qualifier
-
{ CURRENT VALIDTIME | VALIDTIME AS OF date_timestamp_expression | { [ SEQUENCED | NONSEQUENCED ] VALIDTIME } [ period_expression ] } - transaction_time_qualifier
-
{ { CURRENT | NONSEQUENCED } TRANSACTIONTIME | TRANSACTIONTIME AS OF date_timestamp_expression } - CURRENT VALIDTIME
- Specifies that the session valid-time qualifier is current.
- VALIDTIME AS OF date_timestamp_expression
- Specifies that when a SELECT statement refers to a temporal table but omits a valid-time qualifier, the default behavior extracts a snapshot of the table in the valid-time dimension AS OF the date or timestamp value specified by date_timestamp_expression.
date_timestamp_expression can be a constant, scalar UDF, scalar subquery, or business calendar function that evaluates to a date or timestamp value.
- VALIDTIME SEQUENCED VALIDTIME
- Specifies that the session valid-time qualifier is sequenced.
- NONSEQUENCED VALIDTIME
- Specifies that the session valid-time qualifier is nonsequenced.
- period_expression
- Specifies the period of applicability for the sequenced or nonsequenced session valid-time qualifier. The period value must be a constant expression or built-in function and cannot reference any columns.
- CURRENT TRANSACTIONTIME
- Specifies that the session transaction-time qualifier is current.
- TRANSACTIONTIME AS OF date_timestamp_expression
- Specifies that when a SELECT statement refers to a temporal table but omits a transaction-time qualifier, the default behavior extracts a snapshot of the table in the transaction-time dimension AS OF the date or timestamp value specified by date_timestamp_expression.
date_timestamp_expression can be a constant, scalar UDF, scalar subquery, or business calendar function that evaluates to a date or timestamp value.
- NONSEQUENCED TRANSACTIONTIME
- Specifies that the session transaction-time qualifier is nonsequenced.
- AS OF date_timestamp_expression
- Specifies that when a SELECT statement refers to a temporal table but omits the valid-time qualifier, transaction-time qualifier, or both, the default behavior extracts a snapshot of the table in the valid-time dimension, transaction-time dimension, or both dimensions AS OF the value specified by date_timestamp_expression.
date_timestamp_expression can be a constant, scalar UDF, scalar subquery, or business calendar function that evaluates to a date or timestamp value.
- ANSIQUALIFIER
- This is the default for users of ANSI/ISO-compatible temporal tables and syntax.