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Tag: ALTER TABLE

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 Page Corruption In Compressed InnoDB Tables

Sometimes corruption is not what is seems. Corruption in compressed InnoDB tables may be a false positive. Compressed InnoDB tables may hit a false checksum verification failure. The bug (http://bugs.mysql.com/bug.php?id=73689) reveals itself in the error log as follows: 2014-10-18 08:26:31 7fb114254700 InnoDB: Compressed page type (17855); stored checksum in field1 0; calculated checksums for field1: […]

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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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