…What is my recommendation for MySQL 5.6? Is MHA ready for MySQL 5.6? A: My personal recommendation for MySQL 5.6, based on what…/libexec/mysqld: Incorrect information in file: ‘./mysql/servers.frm‘ ERROR: 1033 Incorrect information in file: ‘./mysql/servers.frm‘ Running mysql_install_db under strace,…
Post: Understanding the maximum number of columns in a MySQL table
April 8, 2013 By 5 Comments
… sets of polls: “What is the maximum number of columns in MySQL?” and “What is the minimum maximum number of columns in MySQL?”. Before you read… out what the actual limit is, we must delve further into the FRM file. What is an FRM file? It’s the FoRM file from UNIREG. It’s FRM rather…
Post: How to recover table structure from InnoDB dictionary
April 22, 2013 By 4 Comments
… .frm files is not an option: Table was dropped and innodb_file_per_table is ON Frm file corrupt, zeroed out, lost or SHOW CREATE TABLE crashes MySQL There is yet another source…_FIELDS We need to know what fields form the primary key. The matter is regardless at what position primary key fields are defined…
Post: Is there room for more MySQL IO Optimization?
January 3, 2013 By 11 Comments
… file system cache I would normally have on database server for those things which need to be cached — system files, binary log, FRM files, MySQL MyISAM system tables etc. Starting MySQL 5.5 MySQL uses asynchronous IO which should allow… a look at the graph: What this tells me is there is a lot of untapped potential in MySQL IO as I think we…
Post: MySQL opening .frm even when table is in table definition cache
November 21, 2011 By 8 Comments
… set to 1000. My understanding of this is that MySQL won’t revert to opening the FRM files to read the table definition, but… of the FRM file format to confirm) return the fourth byte for the DB_TYPE. i.e. what storage engine it is. We can…_definition_cache). Further reading: MySQL Forge Internals document on the FRM file format Stewart’s blog post on the FRM file format (from early 2009…
Post: Recovering CREATE TABLE statement from .frm file
December 17, 2008 By 5 Comments
… from .frm file ? Recovering from .frm for Innodb Table If we simply copy .frm file back to the database we will see the following MySQL creative… what we can do is to make sure Innodb has something in its data dictionary so it allows MySQL to succeed displaying .frm file contents: mysql…
Post: Innodb vs MySQL index counts
November 29, 2011 By 6 Comments
…on a test system is simple: create an Innodb table make a copy of the .frm file do an ALTER TABLE…the output of SHOW CREATE TABLE to what Innodb thinks. What Innodb thinks is in the Innodb Data dictionary. The …1, but doesn’t appear in MySQL until 5.6 (if the manual is to be trusted). I’d probably…
Post: More on MySQL Error Messages
April 6, 2011 By 9 Comments
…mysql> drop database test; ERROR 1010 (HY000): Error dropping database (can’t rmdir ‘./test/’, errno: 17) First question you should ask is what is…What is the problem in this case ? It is SELinux denying permission to this file…
Post: Ultimate MySQL variable and status reference list
January 8, 2011 By 4 Comments
… to the amazing MySQL manual, especially the option and variable reference …or forums. So I present to you what is now my newest Firefox toolbar bookmark: … innodb_file_formatblogpercona.commanual innodb_file_format_checkblogpercona.commanual innodb_file_format_maxblogpercona.commanual innodb_file_…
Post: MySQL Error Message Nonsenses
March 16, 2008 By 7 Comments
…is unavailable ? This is especially strange because it should not be so hard to discover this issue – storage engine which is specified in .frm file is… strange file system/OS error until you run perror: [pz@sl1 ~]$ perror 150 MySQL error code 150: Foreign key constraint is incorrectly formed What is…
