EC
1271
MySQLerrorconfigurationhigh confidence

Unknown system variable

Production Risk

Low — the statement fails; no data is changed.

What this means

A SET or SELECT statement referenced a system variable name that MySQL does not recognise.

Why it happens
  1. 1Typo in variable name
  2. 2Variable was removed or renamed in a newer/older MySQL version
  3. 3Plugin providing the variable is not loaded
How to reproduce
trigger — this will error
trigger — this will error
SET GLOBAL nonexistent_var = 1;

expected output

ERROR 1271 (HY000): Unknown system variable 'nonexistent_var'

Fix 1

Check variable name

Check variable name
SHOW VARIABLES LIKE '%keyword%';

Why this works

Lists variables matching a pattern so you can find the correct name.

Fix 2

Verify plugin is loaded

Verify plugin is loaded
SHOW PLUGINS;

Why this works

Plugin variables are only visible when the plugin is active.

What not to do

✕

Version notes

Sources
Official documentation ↗

MySQL 8.0 — 1271 ER_UNKNOWN_SYSTEM_VARIABLE

Content generated with AI assistance and reviewed for accuracy. Found an error? hello@errcodes.dev

← All MySQL errors