[ { CURRENT | NONSEQUENCED } VALIDTIME |
[ SEQUENCED ] VALIDTIME [ period_expression ]
]
merge_statement [;]
- CURRENT VALIDTIME
- Specifies that the merge is current in the valid-time dimension.
- VALIDTIME and SEQUENCED VALIDTIME
- Specifies that the merge is sequenced in the valid-time dimension.
- period_expression
-
Specifies the period of applicability for the DML statement.
The period of applicability must be a period constant expression that does not reference any columns, but can reference parameterized values and the TEMPORAL_DATE or TEMPORAL_TIMESTAMP built-in functions.
The period of applicability can also be a self-contained noncorrelated scalar subquery that is always nonsequenced in the time dimensions regardless of the temporal qualifier for the DML statement.
If a period_expression is specified, the valid-time column cannot be specified or referenced anywhere in the query. If the valid-time column is a derived period column, the component columns cannot be specified or referenced anywhere in the query.If period_expression is omitted, the period of applicability defaults to PERIOD'(0001-01-01, UNTIL_CHANGED)' for a PERIOD(DATE) valid-time column or PERIOD '(0001-01-01 00:00:00.000000+00:00, UNTIL_CHANGED)' for a PERIOD(TIMESTAMP( n ) WITH TIME ZONE) valid-time column, where precision n and WITH TIME ZONE are optional.
- NONSEQUENCED VALIDTIME
- Specifies that the merge is nonsequenced in the valid-time dimension.
- merge_statement
- Specifies the syntax for the conventional form of the MERGE statement.