MySQL Tutorial/Encryption Compression Functions/UNCOMPRESSED LENGTH

UNCOMPRESSED_LENGTH(compressed_string) returns the length that the compressed string had before being compressed.

mysql>
mysql>
mysql> SELECT UNCOMPRESSED_LENGTH(COMPRESS(REPEAT("a",30)));
+-----------------------------------------------+
| UNCOMPRESSED_LENGTH(COMPRESS(REPEAT("a",30))) |
+-----------------------------------------------+
|                                            30 |
+-----------------------------------------------+
1 row in set (0.00 sec)
mysql>
mysql>