1990
MySQLERRORCriticalServerHIGH confidence
MySQL help database is corrupt or missing
Production Risk
Low — only HELP statements are affected; no user data is at risk.
What this means
The MySQL internal help tables (help_topic, help_category, help_keyword, help_relation) are missing, empty, or corrupt, so HELP statements cannot return results.
Why it happens
- 1Help tables were never populated after installation.
- 2Help tables were accidentally dropped or truncated.
- 3A failed upgrade left the help tables in an inconsistent state.
How to reproduce
trigger — this will error
trigger — this will error
HELP 'SELECT';
expected output
ERROR 1990 (HY000): No help entry found for 'SELECT' - help database is corrupt.
Fix
Re-populate the help tables using fill_help_tables.sql
Re-populate the help tables using fill_help_tables.sql
mysql -u root -p mysql < /usr/share/mysql/fill_help_tables.sql
Why this works
This script re-inserts all help content into the mysql.help_* tables.
What not to do
✕
Sources
Official documentation ↗
MySQL 8.0 — 1990 ER_CORRUPT_HELP_DB
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