Syntax - Teradata Vantage - Analytics Database

{ COMPRESS [ constant | ( { constant | NULL } [,...] ) ] |
  COMPRESS_USING_phrase DECOMPRESS_USING_phrase
} [...]

Syntax Elements

COMPRESS_USING_phrase

COMPRESS USING [dbname.] compress_udf

DECOMPRESS_USING_phrase

DECOMPRESS USING [dbname.] decompress_udf

COMPRESS With No Arguments

Compress nulls only.

Note that if you do not specify COMPRESS, nulls are not automatically compressed.

Multivalue Compression (MVC) Specification

COMPRESS

Compress column data using multivalue compression.

constant

A set of values to be compressed.

You can specify a single constant value, or a multivalued, comma-separated list of up to 255 distinct constant values enclosed in parentheses.

NULL

Nulls will be compressed.

NULL can be specified alone, but it must be enclosed in parentheses. This is the same as specifying COMPRESS without an argument.

NULL can be specified with up to 255 constant values in a multivalued, comma-separated list enclosed in parentheses.

Algorithmic Compression (ALC) Specification

COMPRESS USING

Compress column data using algorithmic compression.

DECOMPRESS USING

Decompress column data that was previously compressed using algorithmic compression.

dbname

The name of the database in which the compress or decompress user-defined function (UDF) is stored. If a database name is not specified, the default database used is SYSUDTLIB.

You should create all compress and decompress UDFs in the SYSUDTLIB database. Note that compression functions supplied by Teradata are located in TD_SYSFNLIB.

compress_udf

The name of the UDF used to compress values in the column.

decompress_udf

The name of the UDF used to decompress values in the column.