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Tag: innodb dictionary

Presenting TwinDB Data Recovery Toolkit at the #SFMySQL Meetup

On 5 November, I’ll be speaking about Data Recovery Software for MySQL at the #SFMySQL Meetup. You might want to add Slipped & DROP’d your TABLE? Recover w/TwinDB’s Undrop for InnoDB toolkit to your calendar. There will be a demo, and if you want to try to undrop a table yourself bring in a Linux laptop. Further […]

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Temporary Table Naming Scheme In 5.6 And Before

Benchmarking is a popular topic. People love drawing graphs as much as watching how X is 10% faster than Y; there must be something special about measurements. For a DBA, however, more tangible improvements come from a less popular area of database maintenance. While MariaDB spreads FUD around InnoDB (which still uses it), I have […]

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Resolving ERROR 1050 42S01 At Line 1 Table Already Exists

When ALTER TABLE crashes the MySQL server, it leaves orphaned records in the InnoDB dictionary. It is annoying because next time you run the same ALTER TABLE query, it will fail with error: ERROR 1050 (42S01) at line 1: Table ‘sakila/#sql-ib712’ already exists This post explains why it happens and how to fix it. When […]

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Recover Table Structure From InnoDB Dictionary

When a table gets dropped, MySQL removes the respective .frm file. This post explains how to recover the table structure if the table was dropped. You need the table structure to recover a dropped table from the InnoDB tablespace. The B+tree structure of the InnoDB index doesn’t contain any information about field types. MySQL needs […]

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InnoDB Dictionary

Why Does InnoDB Need A Dictionary An InnoDB dictionary is a set of internal tables InnoDB uses to maintain various information about user tables. It serves as API between a human and the database. While the humans refer to tables by their names, InnoDB works with integer identifiers. The dictionary stores correspondence between table name […]

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