… flush tables with read lock while switching .frm files. When and how it works: auto_increment (removing). Let’s have a simple table with auto_increment we want to get rid of: CREATE TABLE `huge_table` ( `id… that would work for changing table comment as well, however – changing a comment with a help of ALTER TABLE does not rebuild the table, so…
Post: Performance problem with Innodb and DROP TABLE
February 3, 2011 By 23 Comments
…’ve been working with an application which does a lot of CREATE and DROP table for Innodb tables and we’ve discovered DROP TABLE can… design or use innodb_file_per_table=0 for such tables (thankfully you can change this variable online in Innodb Plugin, MySQL 5.5 and Percona Server). Yes. if you’re not using innodb_file_per_table you…
Post: Knowing what pt-online-schema-change will do
November 1, 2012 By 1 Comment
… question: –dry-run and –print. When ran with –dry-run and –print, pt-online-schema-change changes nothing but prints a lot… is copied, so the table is empty. Although the tool does not actually do a lot of work during a dry run… them. In summary: before running pt-online-schema-change with –execute, you should run it first with –dry-run and –print to see…
Post: Heikki Tuuri answers to Innodb questions, Part II
November 4, 2007 By 13 Comments
…s main database, I believe different applications work best on different database brands. Oracle’…. PZ: First Indeed writes are slower with Flash disks compared to Reads because Flash …be possible to implement online reorganize which locks and reorganizes small portions of table online. Q38: Seems …
Post: Migrating to XtraDB Cluster Webinar follow up questions
June 6, 2012 By 3 Comments
…using this the node should be fully functional and online during the entire backup. Q: Can I …affect overall availability? As I said, some ALTER TABLE operations, such as adding and removing indexes, … that won’t work with your change (i.e., your change will prevent replication from working if you …
Post: Percona XtraDB Cluster - installation and setup webinar follow up Q&A
October 28, 2012 By 4 Comments
…a node is down, when it comes back online, you have to perform a state transfer,…. Q: I installed Percona as cluster database working with Zabbix (innodb), do you have a recommended configuration… itself while holding a lock using FLUSH TABLES WITH READ LOCK. MyISAM support is experimental. Apart…
Post: How Percona does a MySQL Performance Audit
November 24, 2008 By 17 Comments
… online …work about 6 months after Peter helped a client. Now, if Peter worked with…tables, I’ll paste in mysql> show global variables like ‘%table_size%’; +———————+———–+ | Variable_name | Value | +———————+———–+ | max_heap_table_size | 268435456 | | tmp_table…
Post: Percona Toolkit 2.1.8 released today with beta support for MySQL 5.6
January 9, 2013 By Leave a Comment
… tools have been verified to work on PXC versions 5.5.28 and newer: pt-table-chcecksum pt-online-schema-change pt-archive…: Fixed bug 1082599: pt-query-digest fails to parse timestamp with no query. Slow logs which include timestamps but no query… zone. Fixed bug 1079341: pt-online-schema-change checks for foreign keys on MyISAM tables. Since MyISAM tables can’t have foreign keys…
Post: Shard-Query turbo charges Infobright community edition (ICE)
May 6, 2011 By 23 Comments
…so large that it was difficult to work with. The ontime flight performance statistics data, available online from the United States Bureau … newly constructed dimension table tables to the staging tables, omitting the dimension columns from the projection, instead replacing them with the dimension …
Post: Intro to OLAP
July 12, 2010 By 10 Comments
… about business intelligence tools, particularly OLAP (or online analytical processing) tools using MySQL and other … in dimension tables. The fact table contains columns which are joined to the dimension tables, such as … BI tools (if you have them) will work with it. MDX is a query language that …
