Many people use mysqldump –single-transaction to get consistent backup for their Innodb tables without making database read only. In most cases it works, but did you know there are some cases when you can get table entirely missing from the backup if you use this technique ? The problem comes from the fact how MySQL’s [...]
Improved InnoDB fast index creation
November 6, 2011 By 4 Comments
One of the serious limitations in the fast index creation feature introduced in the InnoDB plugin is that it only works when indexes are explicitly created using ALTER TABLE or CREATE INDEX. Peter has already blogged about it before, here I’ll just briefly reiterate other cases that might benefit from that feature: when ALTER TABLE [...]
A recovery trivia or how to recover from a lost ibdata1 file
June 3, 2011 By 8 Comments
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 [...]
Ultimate MySQL variable and status reference list
January 8, 2011 By 4 Comments
I am constantly referring to the amazing MySQL manual, especially the option and variable reference table. But just as frequently, I want to look up blog posts on variables, or look for content in the Percona documentation or forums. So I present to you what is now my newest Firefox toolbar bookmark: an option and [...]
mysql_upgrade and Innodb Tables
May 14, 2010 By 8 Comments
Upgrading from MySQL 5.0 to MySQL 5.1 or Percona Server 5.1 you may run into issues with mysql_upgrade – it will identify some tables to be upgraded and will attempt to run REPAIR TABLE for them. This will fail with “The storage engine for the table doesn’t support repair” error message. This seems to confuse [...]
Copying InnoDB tables between servers
July 31, 2009 By 11 Comments
The feature I announced some time ago http://www.mysqlperformanceblog.com/2009/06/08/impossible-possible-moving-innodb-tables-between-servers/ is now available in our latest releases of XtraBackup 0.8.1 and XtraDB-6. Now I am going to show how to use it (the video will be also available on percona.tv). Let’s take tpcc schema and running standard MySQL ® 5.0.83, and assume we want to copy order_line [...]
Should you move from MyISAM to Innodb ?
January 12, 2009 By 59 Comments
There is significant portion of customers which are still using MyISAM when they come to us, so one of the big questions is when it is feasible to move to Innodb and when staying on MyISAM is preferred ? I generally prefer to see Innodb as the main storage engine because it makes life much [...]
A quest for the full InnoDB status
October 31, 2008 By 4 Comments
When running InnoDB you are able to dig into the engine internals, look at various gauges and counters, see past deadlocks and the list of all open transactions. This is in your reach with one simple command —
1 | SHOW ENGINE InnoDB STATUS |
. On most occasions it works beautifully. The problems appear when you have a large spike in [...]
Recovering Innodb table Corruption
July 4, 2008 By 21 Comments
Assume you’re running MySQL with Innodb tables and you’ve got crappy hardware, driver bug, kernel bug, unlucky power failure or some rare MySQL bug and some pages in Innodb tablespace got corrupted. In such cases Innodb will typically print something like this: InnoDB: Database page corruption on disk or a failed InnoDB: file read of [...]
Can MySQL temporary tables be made safe for statement-based replication?
May 26, 2008 By 8 Comments
A while ago I wrote about how to make MySQL replication reliable, part of which is to eliminate temporary tables. The idea is this: if a slave is stopped (or crashed) while a temporary table is open and is then restarted, the temporary table doesn’t exist anymore, and the slave will have problems trying to [...]
