<p>The server cannot access a table because its on-disk format is too old for the running MySQL version.</p>
<p>MySQL Error 1455: ER_OLD_FILE_FORMAT occurs when a table or index was created with an outdated storage format that newer MySQL builds cannot read. Run mysql_upgrade or rebuild the affected table with ALTER TABLE ... ENGINE=InnoDB to restore compatibility.</p>
%s' has an old format, you should re-create the '%s'
Error 1455 signals that MySQL has encountered a table, index, or view definition stored in a legacy on-disk layout that the current server can no longer interpret safely.
It usually surfaces right after an in-place upgrade or when copying files from an ancient server into a newer instance. Any SELECT, INSERT, or DDL touching the outdated table triggers the exception.
Queries will keep failing, replication may stop, and backups cannot be restored while the table remains in its old format. Prompt repair prevents prolonged downtime.
In most cases the mysql_upgrade utility was skipped after upgrading the server binaries. Older MyISAM files or pre-4.1 .frm metadata are incompatible with modern engines until rebuilt.
The quickest solution is to run mysql_upgrade with sufficient privileges; it scans all schemas and converts objects to the newest format.
Single table only: dump the table with mysqldump, drop it, then reload the dump. Multiple tables: execute mysql_upgrade or use mysqlcheck --repair --all-databases.
Always include mysql_upgrade or its in-place alternative mysqlcheck in upgrade run-books. Automate upgrade tests in staging before production rollouts. Monitor the error log for 1455 codes.
Error 124: ER_CHECKREAD is thrown when the table is damaged, while 134: ER_INVALID_TABLE_DEFINITION points to incompatible column definitions. Each requires its own repair path but the prevention steps overlap.
Running the new mysqld binary without converting system tables leaves many user tables in an obsolete file format that the server rejects.
Moving physical files bypasses version checks, so the first query against them raises ER_OLD_FILE_FORMAT.
The replica receives statements referring to tables it has not yet converted, stopping replication with error 1455.
A table created for an engine that is no longer compiled in may be flagged as old format because metadata cannot be decoded.
Indicates that the .MYI index file is corrupted, often seen alongside old format errors.
Triggered by column types that conflict with the current SQL mode; may show up after upgrades.
Occurs when MySQL cannot read the .frm file; sometimes fixed by the same rebuild steps used for error 1455.
mysql_upgrade locks tables only briefly; you can usually run it online, but schedule a maintenance window for large schemas.
If the table was already InnoDB, the command rewrites it in place without changing the engine, simply refreshing the on-disk format.
Yes. The error is platform-agnostic because it is tied to MySQL version differences, not the operating system.
Galaxy surfaces server errors instantly in its IDE, suggests mysql_upgrade commands via its AI copilot, and stores versioned migration scripts so teams never skip upgrade steps.
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