15.00 - Hashing On Bit Patterns, Not Values - Teradata Database

Teradata Database Design

prodname
Teradata Database
vrm_release
15.00
category
User Guide
featnum
B035-1094-015K

Hashing On Bit Patterns, Not Values

The Teradata Database hashing algorithm operates on the bit patterns of the data on which it operates: the internal representation of the data, not its external value.

For example, a numeric value stored as a DECIMAL number with one precision produces a different hash code than the same numeric value stored as a DECIMAL value with a different precision (see “Data Type Considerations” on page 822). Additionally, a number typed as an integer requires only 4 bytes of storage, while its decimal representation might take as many as 8 bytes, depending on the size of the number.