16.20 - Restrictions on the Data Types Involved in Predicates - Teradata Vantage NewSQL Engine

Teradata Vantage™ SQL Functions, Expressions, and Predicates

prodname
Teradata Database
Teradata Vantage NewSQL Engine
vrm_release
16.20
category
Programming Reference
featnum
B035-1145-162K

The restrictions in the following table apply to operations involving predicates and CLOB, BLOB, and UDT types.

Data Type Restrictions
BLOB Predicates do not support BLOB or CLOB data types.

You can explicitly cast BLOBs to BYTE and VARBYTE types and CLOBs to CHARACTER and VARCHAR types, and use the results in a predicate.

CLOB
UDT The LIKE and OVERLAPS logical predicates do not support UDTs.

For EXISTS and NOT EXISTS: Multiple UDTs involved as predicate operands must be identical types because Teradata Database does not perform implicit type conversion on UDTs involved as predicate operands.

A workaround for this restriction is to use CREATE CAST to define casts that cast between the UDTs and then explicitly invoke the CAST function within the operation involving predicates.

For more information on CREATE CAST, see Teradata Vantage™ SQL Data Definition Language Syntax and Examples, B035-1144.

For BETWEEN/ NOT BETWEEN and IN/NOT:
  • Multiple UDTs involved as predicate operands must be identical types because Teradata Database does not perform implicit type conversion on UDTs involved as predicate operands.

    A workaround for this restriction is to use CREATE CAST to define casts that cast between the UDTs and then explicitly invoke the CAST function within the operation involving predicates.

  • UDTs involved as predicate operands must have ordering definitions.

    Teradata Database generates ordering functionality for distinct UDTs where the source types are not LOBs. To create an ordering definition for structured UDTs or distinct UDTs where the source types are LOBs, or to replace system-generated ordering functionality, use CREATE ORDERING.

For more information on CREATE CAST and CREATE ORDERING, see Teradata Vantage™ SQL Data Definition Language Syntax and Examples, B035-1144.