Search Results for: recovery innodb tables

On Character Sets and Disappearing Tables

The MySQL manual tells us that regardless of whether or not we use “SET FOREIGN_KEY_CHECKS=0″ before making schema changes, InnoDB will not allow a column referenced by a foreign key constraint to be modified in such a way that the foreign key will reference a column with a mismatched data type. For instance, if we […]

Percona Testing: Innodb crash / recovery tests available

Not everyone may know this, but there are precious few innodb crash recovery tests available. Some folks have noticed this and asked for something to be done about it, but unfortunately, no tests have been created for the main MySQL branch. The MySQL at Facebook branch has a number of tests that are quite interesting.  […]

A recovery trivia or how to recover from a lost ibdata1 file

A few day ago, a customer came to Percona needing to recover data. Basically, while doing a transfer from one SAN to another, something went wrong and they lost the ibdata1 file, where all the table meta-data is stored. Fortunately, they were running with innodb_file_per_table so the data itself was available. What they could provide […]

Lost innodb tables, xfs and binary grep

Before I start a story about the data recovery case I worked on yesterday, here’s a quick tip – having a database backup does not mean you can restore from it. Always verify your backup can be used to restore the database! If not automatically, do this manually, at least once a month. No, seriously […]