Error
Error Code:
1847
MySQL Error 1847: COPY Algorithm Lock Required
Description
This error indicates that a `COPY` algorithm, typically used during an `ALTER TABLE` operation, failed to acquire the necessary exclusive table lock. The `COPY` algorithm requires sole access to rebuild the table, and this error occurs when another process or configuration prevents such a lock from being obtained.
Error Message
COPY algorithm requires a lock
Known Causes
3 known causesActive Transactions Preventing Lock
Other database sessions or long-running transactions are currently holding locks on the table, preventing the `COPY` algorithm from acquiring an exclusive lock.
Incompatible ALGORITHM or LOCK Clause
The `ALTER TABLE` statement might have specified `ALGORITHM=INPLACE` or `LOCK=NONE` when the operation intrinsically requires `ALGORITHM=COPY` and an exclusive lock.
Operation Requiring COPY Algorithm
The specific `ALTER TABLE` operation being performed is not supported `INPLACE` by the storage engine, thus forcing the `COPY` algorithm which then fails to get a lock.
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