…column, we have converted a lot of point primary key lookups to one or more range primary key lookup. Thereby, converting Random access to…to execute, ~11 hours in case of MySQL 5.5 and ~5 hours in case of MySQL…
Post: A recovery trivia or how to recover from a lost ibdata1 file
June 3, 2011 By 7 Comments
…column. With a modified schema, the recovery completed. The customer was able to download the tables in MyISAM format and then he just convert…
Post: How to recover deleted rows from an InnoDB Tablespace
February 20, 2012 By 3 Comments
…to the error log. mysql (employees) > CREATE TABLE innodb_table_monitor (id int) ENGINE=InnoDB; TABLE: name employees/salaries, id 18, flags 1, columns…table_defs.h so it will be necessary to recompile the tool. To help us in the task of converting the schema definition to…
Post: TMP_TABLE_SIZE and MAX_HEAP_TABLE_SIZE
January 19, 2007 By 16 Comments
…to it you should increase tmp_table_size to appropriate value and avoid using blob/text columns which force table…table after which it will be converted to MyISAM. To make things more confusing this is not what you would read in MySQL…
Post: Flexviews - part 3 - improving query performance using materialized views
April 4, 2011 By 12 Comments
…to convert SQL to the Flexviews API (see convert.php below) Refresh methods The incremental refresh method The incremental refresh method uses table…how you can use this summary to calculate the number of lines in the order_lines table, three orders of magnitude more quickly than COUNT(*). mysql…
Comment: Database problems in MySQL/PHP Applications
August 11, 2006 By 12 Comments
…to do row lookups by multiple columns of varchars is likely. Don’t do it. I can think of…of MySQL. If nothing else, it makes replicating a subset of the data much easier. > Regarding if you use many tables…of converting your varchars to chars for example), then having to…
Post: Innodb row size limitation
April 7, 2011 By 11 Comments
…mysql…converting from a native language character set to…table definition, but at row insertion. You may just have a table with 50 variable length columns…columns aren’t requested as part of a row-read, they don’t have to be touched at all. Of…
Post: Lost innodb tables, xfs and binary grep
November 9, 2010 By 11 Comments
…how data was lost: MySQL had a dedicated partition on XFS file system Server was running innodb_file_per_table…to have a lot of data to scan and you have to…of percona recovery toolset, with some additional converters so we can match against various date/time columns…
Post: Using VIEW to reduce number of tables used
September 28, 2007 By 12 Comments
…columns (to keep it simple). There are one table per user so we have post123 table which keeps posts for user number 123 etc. Converting…to underlying table MySQL tries to set it to default, which does not work as it has to be different for each of…
Post: Using MMM to ALTER huge tables
March 27, 2008 By 11 Comments
…to changes that really require table to be rebuilt – adding/dropping columns or indexes, changing data type, converting data to different character set – MySQL…of “downtime” was really trivial. I’d like to share my experience. The article does not cover MMM installation nor how to…
