16.20 - Usage Notes - Advanced SQL Engine - Teradata Database

Teradata Vantage™ - SQL Operators and User-Defined Functions

Advanced SQL Engine
Teradata Database
Release Number
Release Date
April 2020
Content Type
Programming Reference
Publication ID
English (United States)

Uncompressed character data in Teradata Database requires 2 bytes per character when storing Unicode data. LZCOMP takes Unicode character input, compresses it using the Lempel-Ziv algorithm, and returns the compressed result.

LZCOMP provides good compression results for long Unicode strings, but might not be as effective for short strings. It can also provide good results for medium strings that have many repeating characters.

Although you can call the function directly, LZCOMP is normally used with algorithmic compression (ALC) to compress table columns. If LZCOMP is used with ALC, nulls are also compressed if those columns are nullable.