MERGE Syntax Elements (Temporal Form) - Analytics Database - Teradata Vantage

Temporal Table Support

Deployment
VantageCloud
VantageCore
Edition
Enterprise
IntelliFlex
VMware
Product
Analytics Database
Teradata Vantage
Release Number
17.20
Published
June 2022
Language
English (United States)
Last Update
2023-10-30
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lifecycle
latest
Product Category
Teradata Vantage™
CURRENT VALIDTIME
Specifies that the merge is current in the valid-time dimension.
Either the target table or the source table must support the valid-time dimension.
CURRENT DML modifications can cause serializability issues for concurrent transactions. See Potential Concurrency Issues with Current Temporal DML for information on avoiding these issues.
VALIDTIME and SEQUENCED VALIDTIME
Specifies that the merge is sequenced in the valid-time dimension.
Either the target table or the source table must support 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.
Either the target table or the source table must support the valid-time dimension.
merge_statement
Specifies the syntax for the conventional form of the MERGE statement.
For details, see Teradata Vantage™ - SQL Data Definition Language Syntax and Examples, B035-1144.