… 5.5 with addition of user variables, stored procedures, prepared statements etc which can be …size, bytes 128849002496 Free buffers 1 Database pages 8252672 Old database pages 3046376 Modified db pages 23419 …swap file used space gradually growing and there are “swap outs” but a lot less “swap ins” …
Post: MySQL File System Fragmentation Benchmarks
March 21, 2008 By 28 Comments
…in 1 10 100 1000 10000; do ./benchmark.php $i 10000000; mysql -e’drop database test1′; mysql -e’create database… be because ext3 does not like so many files in directory or because random updates to 10000 …well) – Innodb suffers fragmentation less if it stores different tables in different files…
Post: PHP Sessions - Files vs Database Based
March 27, 2007 By 38 Comments
… may think changing PHP session handler from file based to database driven is fully transparent. In many cases it is, sometimes however it… will be serialized for single user on database level. If you change to store PHP sessions in MySQL instead this effect may be… get back your old file based session behavior with MySQL Sessions ? If you have dedicated connection to session database and use Innodb…
Post: How innodb_open_files affects performance
November 18, 2009 By 4 Comments
…in .ibd files plus some space allocated in system tablespace. So if you create Innodb tables you better store some data in…database… If Innodb detects it is not shut down properly it will scan all .ibd files… downs for replacing open files in the list. I guess Heikki knows how to implement LRU in …
Comment: PHP Sessions - Files vs Database Based
March 27, 2007 By 38 Comments
…. Consider the case when you had 1 Web box and file sessions and it can’t keep up so you’re… avoid having sessions set up on NFS file system. So you end up storing them in database and your application breaks. Now the question… first. You also can consider killing previous page view queries in some cases. Regarding session purge – this is another thing which…
Post: High-Performance Click Analysis with MySQL
December 22, 2008 By 13 Comments
… store everything in the database. Instead, store the source data in some fashion that you can reload later, such as flat files, and build support in the database…-scale database server for the initial insertion, because you can write CSV files with any programming language. Naturally, CSV files don’t store…
Post: MySQL Storage Engines - PBXT
May 14, 2007 By 6 Comments
… file is taking about 8 bytes per row as I understand so it should be very small and well cached in database cache… data part and dynamic data parts stored in separate files. Dynamic length part is stored in file called “Data Log File” which is quite confusing to my taste. So all together we have row which is stored in 3…
Post: Lost innodb tables, xfs and binary grep
November 9, 2010 By 11 Comments
… used to restore the database! If not automatically, do this manually, at least once a month. No, seriously – in most of the… innodb_file_per_table There was a production master and two slaves, all had same setting Developer accidentally ran DROP DATABASE X… match it. InnoDB would internally store integers in 4-bytes rather than 10 bytes if it were stored as a sequence of characters…
Post: Database problems in MySQL/PHP Applications
August 11, 2006 By 12 Comments
… more modest. DVD Store was special type of application which was designed to have very simple logic besides database – in most cases you… applications using multiple databases to group tables by certain logic, such as you do with directories to group files. I think this… are OS and File System dependent, others correspond to Innodb storage engine or using innodb_file_per_table option in particular. 4. Not…
Post: Heikki Tuuri answers to Innodb questions, Part II
November 4, 2007 By 13 Comments
… to Oracle’s main database, I believe different applications work best on different database brands. Oracle’s main database has a very competent… using solid state disks for storing ib_log* files; I know that innodb writes files in the log file group in a round robin fashion. I… the first file in a log file group. My questions are: What is always being written to the first file in the log file group? HT…
