… gave some information about possible benefits from using new InnoDB file format but in this post I’d like to share… decided to try to convert customer’s data to Barracuda file format using new InnoDB plugin recently released by Oracle. First… entire PRIMARY index in memory (TEXT and BLOB fields are stored off-page in this format) and all our lookups weren…
Post: PHP Sessions - Files vs Database Based
March 27, 2007 By 38 Comments
… one of our customers. If you use file based sessions PHP will lock session file for whole script execution duration, which means… for single user on database level. If you change to store PHP sessions in MySQL instead this effect may be no… lock tables. So how you can get back your old file based session behavior with MySQL Sessions ? If you have dedicated…
Post: How long is recovery from 8G innodb_log_file
December 22, 2010 By 11 Comments
… of improvements in Percona Server is support of innodb_log_file_size > 4G. This test was done using Percona Server 5… 23sec and for 144GB innodb_buffer_pool_size with data stored on RAID10: 101220 23:46:01 InnoDB: Database was not…
Post: High-Performance Click Analysis with MySQL
December 22, 2008 By 13 Comments
…’t store everything in the database. Instead, store the source data in some fashion that you can reload later, such as flat files… tasks on it. Storing a little meta-data about each file can help a lot. Store the ranges of values for…, because you can write CSV files with any programming language. Naturally, CSV files don’t store as compactly on disk as [Compressed…
Post: High availability for MySQL on Amazon EC2 – Part 2 - Setting up the initial instances
June 29, 2010 By 9 Comments
… $_; if (/^RESERVATION/) { $SecGroup = $fields[3]; } if (/^INSTANCE/) { $IPAdd = $fields[17]; $STORE = $fields[20]; $Instance_ID= $fields[1]; $AMI_ID= $fields[… Heartbeat, Pacemaker will come later. Heartbeat needs 2 configuration files, /etc/ha.d/authkeys for cluster authentication and /etc/…
Post: MySQL Backup tools used by Percona Remote DBA for MySQL
March 13, 2013 By 8 Comments
… primary server so you can perform point in time recovery. Store your binlogs offsite for disaster recovery scenarios. Run pt-table… is very convenient feature and allows you to cost effectively store long term backups with little additional work Tips/Tricks: –add…. Given both our mydumper and xtrbackup are seperated by file, for files that don’t change they can be easily hardlinked to…
Post: Data compression in InnoDB for text and blob fields
May 30, 2012 By 2 Comments
… original InnoDB Antelope file format you have the choice of ROW_FORMAT=COMPACT and ROW_FORMAT=REDUNDANT where InnoDB stored the first… (BLOB, VARCHAR, TEXT) in the index record, and the remainder stored in overflow pages. COMPACT became the default after MySQL 5… responsible for 90% of space usage hence compressing only externally stored blobs provided substaintial advantages. Why did we choose a KEY…
Post: Can MySQL temporary tables be made safe for statement-based replication?
May 26, 2008 By 8 Comments
…binary logs: master > show master status; +——————+———-+————–+——————+ | File | Position | Binlog_Do_DB | Binlog_Ignore_DB | +——————+———-+————–+——————+… I also created a version of the stored procedure that doesn’t begin and …
Post: 10+ Ways to Crash or Overload MySQL
November 13, 2007 By 20 Comments
… MyISAM tables. You can also use similar technique with innodb_file_per_table. However you can’t control growth of Innodb… run their queries. Stored Procedures – How much memory can stored procedure allocate ? say can you create 1000 variables in stored procedure and set… not think tight memory allocation policy is enforced. Stored Procedures Cursors – Cursors inside of stored procedures are implemented as temporary tables, so…
Comment: Star Schema Bechmark: InfoBright, InfiniDB and LucidDB
January 2, 2012 By 48 Comments
… and all data must be stored in one place (without said joins). Column Store = Each column is a file that can be scanned (oversimplification). Joins can be used to put data together. Row Store = Each… in one file unless you do a fake-join in your application. For most purposes, column stores behave like row stores. Joins work…
