COMPRESS

Syntax

COMPRESS(string_to_compress)

Description

Compresses a string and returns the result as a binary string. This function requires MariaDB to have been compiled with a compression library such as zlib. Otherwise, the return value is always NULL. The compressed string can be uncompressed with UNCOMPRESS().

The have_compress server system variable indicates whether a compression library is present.

Examples

SELECT LENGTH(COMPRESS(REPEAT('a',1000))); +------------------------------------+ | LENGTH(COMPRESS(REPEAT('a',1000))) | +------------------------------------+ | 21 | +------------------------------------+  SELECT LENGTH(COMPRESS('')); +----------------------+ | LENGTH(COMPRESS('')) | +----------------------+ | 0 | +----------------------+  SELECT LENGTH(COMPRESS('a')); +-----------------------+ | LENGTH(COMPRESS('a')) | +-----------------------+ | 13 | +-----------------------+  SELECT LENGTH(COMPRESS(REPEAT('a',16))); +----------------------------------+ | LENGTH(COMPRESS(REPEAT('a',16))) | +----------------------------------+ | 15 | +----------------------------------+

See Also

• Automatic compression of columns

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