<p>MySQL raises Error 1815 when the server hits an unexpected internal problem and aborts the current statement.</p>
<p>MySQL Error 1815: ER_INTERNAL_ERROR signals that the server encountered an unexpected internal condition and stopped the query. Review the MySQL error log, repair or rebuild any corrupted tablespaces, disable faulty plugins, and restart the server to resolve the issue.</p>
Internal error: %s
MySQL returns Error 1815 with SQLSTATE HY000 when the server detects a condition that should never occur during normal operation. The message Internal error: %s is a generic placeholder that the server replaces with a more specific explanation in the error log. Queries fail immediately and any open transaction may be rolled back.
This error signals a bug, corrupted metadata, or a severe resource issue inside the storage engine. Because the fault originates inside the server, simply retrying the statement rarely works until the root cause is removed.
Most instances trace back to storage engine bugs, corrupted InnoDB pages, missing .frm files, or incompatible plugin code. Hardware faults such as disk errors can also surface as internal errors when InnoDB cannot read or write critical pages.
Configuration mistakes, for example enabling an experimental feature without the required compile options, may leave the server in an inconsistent state that triggers Error 1815 at runtime.
Read the mysqld error log first; the line following Error 1815 contains the real reason. Isolate the database or table mentioned and run CHECK TABLE or mysqlcheck to identify corruption.
If corruption is confirmed, dump unaffected data, rebuild the table with CREATE TABLE ... LIKE or recover from backup. For plugin or configuration issues, disable the offending component and restart the server.
When Error 1815 appears during ALTER TABLE, the table is usually corrupted; export the data with SELECT ... INTO OUTFILE, drop the table, recreate it, and reload the data.
If the error fires at startup, InnoDB system tablespace may be damaged. Restore ibdata* and ib_logfile* from a known-good backup or initialize a fresh instance and import dumps.
Run regular CHECK TABLE and backups to catch corruption early. Keep MySQL upgraded to a supported release with known bug fixes. Use ECC memory and reliable storage to reduce hardware-induced corruption.
Apply configuration changes in a staging environment first. Avoid experimental plugins on production systems. Monitor the error log in real time and alert on any ER_INTERNAL_ERROR entry.
Errors 1812 (ER_TABLESPACE_IS_DISABLED) and 2006 (MySQL server has gone away) often accompany internal failures. They point to similar corruption or resource exhaustion issues and can be resolved with the same diagnostic steps.
Corrupted InnoDB or MyISAM pages prevent the server from reading essential metadata, resulting in an internal error.
When a .frm or .ibd file is deleted or altered outside MySQL, the server cannot reconcile dictionary entries and throws Error 1815.
Third-party components compiled for a different version of MySQL can crash or trigger safeguard assertions that surface as ER_INTERNAL_ERROR.
Disk read/write failures, power loss, or RAID controller problems may cause incomplete I/O that the storage engine reports as an internal error.
Enabling experimental features without proper prerequisites can leave the server in an inconsistent state, leading to Error 1815 during routine queries.
Occurs when InnoDB tablespace cannot be opened, usually a precursor to Error 1815. Fix by enabling the tablespace or recovering from backup.
Indicates the server crashed or closed the connection after an internal failure; investigate logs for a preceding Error 1815.
Low memory can cause the storage engine to abort operations and surface as internal errors.
Corruption is common but not the only cause. Misconfigured plugins, hardware faults, and software bugs can also raise the error.
A restart may clear memory state but will not fix underlying corruption or configuration problems. Investigate the root cause first.
Yes. When the server encounters an internal error it usually rolls back the current statement and any active transaction.
Galaxy highlights server error messages in real time, encourages versioned queries, and simplifies running CHECK TABLE commands so teams spot corruption early.
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