Duplicate row control.
If you do not specify SET or MULTISET, the default table kind depends on the session mode.
- In ANSI session mode, the default table kind is MULTISET. Duplicate rows are allowed.
- In Teradata session mode, the default table kind is SET. Duplicate rows are not allowed.
- MULTISET
- Duplicate rows are allowed.
- If there are uniqueness constraints on any column or set of columns in the table definition, the table cannot have duplicate rows even if you specify MULTISET.
- Some client utilities have restrictions with respect to MULTISET tables. See CREATE TABLE in
Teradata Vantage™ - SQL Data Definition Language Detailed Topics
, B035-1184
.
- SET
- Duplicate rows are not allowed.
- If the only column in the table is its QITS column, then you cannot specify SET. In this case, the table must be defined, either implicitly or explicitly, as MULTISET. See QITS_column_name.