… Percona Server 5.6.10 sandbox: description=MySQL driver=com.mysql.jdbc.Driver connectionSpec=jdbc:mysql://127.0.0.1:5610/schemaspy driverPath… tool. There are additional tabs: Tables – Names, number of children, parents, count of columns, row counts, and comments — a great way for…
Post: Understanding the maximum number of columns in a MySQL table
April 8, 2013 By 5 Comments
…: “What is the maximum number of columns in MySQL?” and “What is the minimum maximum number of columns in MySQL?”. Before you read on… like NEXT_NUMBER fields (what we know today as auto_increment), CASEUP and CASEDN fields which although not implemented in MySQL, the defines… play around the maximum number of columns is this: /* Hack to avoid bugs with small static rows in MySQL */ reclength=max(file->min…
Post: Is Synchronous Replication right for your app?
May 14, 2013 By 18 Comments
…don’t touch the same row. Row locks are held for …MySQL replication from this instance, since MySQL replication is asynchronous. What about semi-sync MySQL… each autocommit is retried only the number of times specified by this …deadlock error. This is not implemented for full BEGIN … COMMIT multi…
Post: How Can Percona MySQL Server Development Services Help ?
January 28, 2013 By 3 Comments
… row format in memory engine is an example of such a feature. Plugins – Plugins are a great way to implement new MySQL server features in many areas while keeping them easily maintainable. Customers have requested that we implement or include a numbers…
Post: MySQL 5.5 and MySQL 5.6 default variable values differences
February 21, 2013 By 8 Comments
…=on,index_merge_union=on,inde | +—————————————————+——————————————+——————————————+ 56 rows in set (0.05 sec) Lets …it implemented as number of different variables which would make more sense in my opinion. MySQL …
Post: DROP TABLE and stalls: Lazy Drop Table in Percona Server and the new fixes in MySQL
June 22, 2012 By 33 Comments
… average performance numbers because they …rows table: sysbench –test=oltp –oltp-table-size=20000000 –mysql-table-engine=innodb –mysql-socket=/tmp/mysql_sandbox5524.sock –mysql…implementation is MySQL 5.5.15, the version of MySQL used for benchmarking the new DROP TABLE implementation is MySQL…
Post: Missing Data - rows used to generate result set
July 20, 2008 By 15 Comments
… number of rows returned. What I would like to see (for example as another slow query log record) is the number of rows which MySQL used to generate result set. Comparing this number with number of rows query actually accessed we can… that easy to implement it in the general sense as you can’t always track the future of individual row. Queries with…
Post: Using Flexviews - part two, change data capture
March 25, 2011 By 26 Comments
… expensive. A change data capture tool can be used to implement an efficient way of refreshing them. What is Change Data…=row to process SBR changes from a MySQL master. I’ll talk more about that in another blog post. FlexCDC does not implement…. This is generally only useful if you have a small number of tables, and you want to track changes on all…
Post: Implications of Metadata Locking Changes in MySQL 5.5
February 1, 2013 By 9 Comments
… large number of MySQL 5.0 and 5.1 installations that would upgrade or are in the process of upgrading to MySQL 5…`.`test` mapped to number 17 #130201 11:21:35 server id 1 end_log_pos 829 Update_rows: table id 17 flags… implementation of Metadata Locking was changed, starting MySQL 5.5.3. Let’s see how this works now. Metadata Locking behavior starting MySQL…
Post: Dynamic row format for MEMORY tables
September 6, 2011 By 5 Comments
… limitation. In 2008 Igor Chernyshev of eBay implemented true-VARCHAR support for MEMORY tables for MySQL 5.0. Although this patch did… for both row formats. (Speaking very strictly, the VM Peak value is not comparable due to slightly different number of rows inserted). In the second test we check if the dynamic row format delivers the memory…
