MySQL error in file: /engine/init.php at line 393

Error Number: 3

The Error returned was:
Error writing file '/tmp/MY9MZk6m' (Errcode: 28 - No space left on device)

SQL query:

SELECT category, COUNT(*) AS count FROM dle_post WHERE approve=1 AND date < '2023-12-07 02:53:52' GROUP BY category