Error
Error Code:
1799
MySQL Error 1799: Online Index Log Exceeded
Description
This error indicates that an online index creation operation (ALTER TABLE ... ADD INDEX ALGORITHM=INPLACE) failed. It occurs when the volume of data modifications (inserts, updates, deletes) on the table during the DDL process exceeds the `innodb_online_alter_log_max_size` limit. MySQL uses this log to track changes and ensure data consistency during online schema changes.
Error Message
Creating index '%s' required more than 'innodb_online_alter_log_max_size' bytes of modification log. Please try again.
Known Causes
4 known causesHigh Table Write Activity
Significant concurrent insert, update, or delete operations on the target table during online index creation quickly fill the modification log.
Insufficient Log Size Configuration
The `innodb_online_alter_log_max_size` server variable is set too low relative to the table's size and ongoing write activity.
Very Large Table
Creating an index on an extremely large table can take a long time, increasing the window for concurrent modifications to accumulate.
Prolonged DDL Operation
Factors causing the index creation to take an unusually long time (e.g., I/O bottlenecks) increase the likelihood of log overflow.
Solutions
Coming SoonDetailed step-by-step solutions for this error are being prepared. In the meantime, try these general troubleshooting tips:
General Troubleshooting Tips
- Check the error message carefully for specific details
- Review recent changes that might have caused the error
- Search for the exact error code in the official documentation
- Check log files for additional context
- Try restarting the application or service