16.20 - Restrictions on the Data Types Involved in Predicates - Advanced SQL Engine

16.20 - Restrictions on the Data Types Involved in Predicates - Advanced SQL Engine - Teradata Database

Teradata Vantage™ - SQL Functions, Expressions, and Predicates

Product

Advanced SQL Engine

Teradata Database

Release Number

16.20

Published

March 2019

Language

English (United States)

Last Update

2020-03-25

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kby1472250656485

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.

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.