String Functions - Learning MySQL and MariaDB - page 233

UNCOMPRESS() . It returns NULL if the string is not compressed or if MySQL wasn't
compiled with zlib :
SELECT UNCOMPRESS(birding_background) AS Background
FROM humans
WHERE name_first = 'Melissa' AND name_last = 'Lee' \G
*************************** 1. row ***************************
Background: lengthy background...
For small amounts of text like this, compression takes more space than the plain text. But
for large amounts of text, it will save plenty of space. So use it sparingly and where appro-
priate.