16.20 - Data Type Evaluation - 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

Different data types define equality and inequality differently. The following table explains the foundations for how the various data types are compared:

This data type … Is evaluated in this way …
Numeric Algebraically, with negatives considered to be smaller irrespective of their absolute value.
Byte Bit-by-bit from left to right. A 0 bit is less than a 1 bit.
  • If every pair comparison is equal, then the two byte string are equal.
  • If any pairwise comparison is not equal, then that comparison determines the result.
  • If two byte strings of different lengths are compared, then the shorter string is padded to the right with binary zeros to make the lengths equal prior to making the comparison.
Character Character-by-character from left to right. Exact comparisons depend on the collation sequence assigned and whether the comparison is case specific or case blind.
The available collations are:
  • ASCII
  • EBCDIC
  • MULTINATIONAL
  • CHARSET_COLL
  • JIS_COLL

If every pairwise comparison is equal, then the two character strings are equal.

If any pairwise comparison is not equal, then that comparison determines the result.

For more information on character comparison, see Comparison of Character Strings of Unequal Length.

DateTime Chronologically.

For information on how Time Zone affects Time comparison, see "Time Zone Sort Order" in Teradata Vantage™ Data Types and Literals, B035-1143.

Interval According to sign and magnitude.
Period Assuming p1 and p2 are Period expressions or derived periods, the evaluation of a Period comparison predicate uses the following logic:

IF BEGIN(p1) = BEGIN(p2) is TRUE, return END(p1) operator END(p2)

ELSE return (BEGIN(p1) operator BEGIN(p2))

For details on BEGIN and END, see "Period Functions and Operators" in Teradata Vantage™ Data Types and Literals, B035-1143.

UDT According to the ordering definition of the UDT.

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 ORDERING, see Teradata Vantage™ SQL Data Definition Language Syntax and Examples, B035-1144.