…to change…to allow replication to resume as soon as possible. An example configuration tuning flow control in a master/slave cluster might be: mysql…4 0 3 0 4…from the Synced to the Donor/Desynced state. Donors in that state will continue to…
Post: MySQL Upgrade Webinar Questions Followup
June 28, 2012 By 7 Comments
…MySQL 5.0 to 5.5 for MyISAM tables? MyISAM have not been getting any significant development since MySQL 4.1, so in-place upgrade of MySQL 5.0 to MySQL 5.5 should be rather safe from data standpoint. There are still possibilities for sorting order and data type related changes,…
Post: MySQL performance: Impact of memory allocators (Part 2)
March 8, 2013 By 12 Comments
…allocators up to 4 vcpu, so on charts below I will highlight results from 4 to 32… distribution. OLTP_RO test consists of 5 select queries – select_ranges, select_order…changes re: page run allocation and dirty page purging may have some correlation with decreasing performance in workloads with MySQL…
Post: Percona Server on the Raspberry Pi: Your own MySQL Database Server for Under $80
February 25, 2013 By 10 Comments
…to see if your password change worked as expected, and install Percona Server from…from extra… libmysqlclient-5.5.30-1-armv6h 3.2 MiB 435K/s 00:08 [########################################################] 100% mysql-clients-5.5…
Post: MySQL Indexing Best Practices: Webinar Questions Followup
August 16, 2012 By 4 Comments
…FROM TBL WHERE hash=crc32(‘string’) AND string=’string’ The other thing you need to consider is string comparison in MySQL… clause better than BETWEEN? A: IN(2-4) will not do what you’re implying… best setup for 5 indexes to differ only by first column. Regarding changing primary key to include such …
Post: Implications of Metadata Locking Changes in MySQL 5.5
February 1, 2013 By 9 Comments
…changes to the table metadata, a table ALTER that alters a big table can keep executing without any hindrance, copying rows from…to get depleted. There are some other interesting consequences as well for application that use MySQL versions prior to 5.5…
Post: Realtime stats to pay attention to in Percona XtraDB Cluster and Galera
November 26, 2012 By 4 Comments
… PXC node. In that spirit, I just today pushed some changes to the ‘wsrep’ report, and I thought I’d go over… with the aim to show folks what they should be watching (at least from my opinion, this is subject to change!). First, let’s… 0 70 85 108K 124K 0.0 0 17 0 4 19:17:06 trime P 3 3 node3 Sync T… 0 65 93 101K 135K 0.0 0 14 1 5 19:17:09 trime P 3 3 node3 Sync T…
Post: Upgrading MySQL
January 5, 2010 By 24 Comments
…to different major version, especially if you skip over one. MySQL 5.0 to 5.1 upgrade is a lot safer upgrade path than 4.1 to 5…MySQL 5.1 with no problems in most cases. When storage type changes, such as DECIMAL field got whole another meaning in MySQL 5.0 MySQL…
Post: MySQL 4 to MySQL 5 Upgrade performance regressions
June 6, 2007 By 8 Comments
… MySQL 4.1 to 5.0 upgrade notes ? ? Furthermore if there were no good ideas how to make XA to…change to do with MySQL 4 also because 100% durable transactions are not required anyway and it would allow to…on MySQL 4.1 until MySQL has taken it away from you as already happened with MySQL 4.0. MySQL 5.0…
Post: How adding another table to JOIN can improve performance ?
August 1, 2008 By 12 Comments
…A BETWEEN 5 and 10…to this problem – using IN list instead of range or UNION which however require rather serious application changes…to get list of days matching range from some pre-generated table and use the join to retrieve the rows from original table: mysql… PRIMARY key_len: 4 ref: NULL rows: 10 …
