In MySQL, filesort is the catch-all algorithm for producing sorted results for ORDER-BY or GROUP-BY queries. MySQL has two algorithms for filesort, both the original and the modified algorithms are described in the user manual.  The most commonly used algorithm is the so called modified algorithm, it is used for all cases except when BLOB and TEXT column are involved.

In 5.7.3, Tor Didriksen in the optimizer team introduced one more optimization that applies to the modified algorithm.  Let us first take a look at how MySQL´s modified filesort algorithm worked up to 5.7.2.

1. Read the rows that match the WHERE clause.
2. For each row, record a tuple of values consisting of the sort key value and the additional fields referenced by the query.
3. When the sort buffer becomes full, sort the tuples …

In addition to my recent post, I just had to go into using the –use-tts for specific tables and selective backup sets.

As all my schemas were employeesn, I thought it would be a good idea to run:

mysqlbackup -uroot --socket=/tmp/mysql.sock --backup-dir=/home/mysql/MEB/restore \
--with-timestamp --use-tts --include=employees* backup

as I want all the tables. If I only wanted a specific table, say ‘salaries’ I could have done:

mysqlbackup -uroot --socket=/tmp/mysql.sock --backup-dir=/home/mysql/MEB/restore \
--with-timestamp --use-tts --include=employees*\.*salaries backup

and backup just the ‘salaries’ tables but from all the employeesn databases.

then.. be a mean little dba:

drop database employees;
drop database employees10;
drop database employees11;
..
..
drop database employees2;
drop database employees20;
drop database …

Twitter’s Calvin Sun

Twitter’s Calvin Sun (@Calvinsun2012) is looking forward to the fast-approaching Percona Live MySQL Conference and Expo this April 1-4 in Santa Clara, Calif. He’ll be speaking, yes, but he’s also looking forward to learning from his peers – particularly those at Facebook. Both companies, he explained, are in the rather unique positions of unprecedented rapid growth and ever-expanding performance demands.

Calvin is a senior engineering manager at Twitter, where he manages MySQL development. Prior to that, he managed the InnoDB team at Oracle. Calvin also worked for MySQL Inc. from 2006 to 2008, managing MySQL storage engines development. He has over 15+ years of database development experience.

He said MySQL is the data storage technology behind …

The MySQL developer tools team at Oracle is excited to announce the availability of MySQL Workbench 6.0.9.

MySQL Workbench 6.0 is the GUI Development and Administration tool for MySQL.

Changes in MySQL Workbench 6.0.9 (2014-02-05)

This section documents all changes and bug fixes applied to MySQL Workbench since the release of 6.0.8.

Functionality Added or Changed

•  The restore operation can restore to a different schema.
  

Bugs Fixed

•  MySQL Workbench now builds on Debian 7.0-unstable.
•  Ubuntu 13.10 is now supported.
•  Fedora 20 is now supported
•  On Linux, the Cancel button was written as "Cance" on some systems, depending on the GTK theme used on the system.
•  Sometimes, when exporting an EER diagram to SQL, the generated SQL code did not …

Monitoring MySQL at Scale
Wednesday, February 19, 2014

50 Tips to Boost MySQL Performance
Wednesday, February 26, 2014

http://www.mysql.com/news-and-events/web-seminars/developing-windows-applications-with-mysql-part-iii-migrating-from-microsoft-sql-server-to-mysql/

Thursday, February 27, 2014

Continuing on from Part 3….

SAP is all about Enterprises and as such, used all the Enterprise features of databases. This is a much different application than every user of MySQL so far (which were often web applications, and increasingly being used at scale). This was “MySQL focuses on Enterprise”.

This is 2003: before VIEWS, before stored procedures, before triggers, before cursors, before prepared statements, before precision math, before SQL access to logs, before any real deadlock info, before you could use a / in a table name, before any performance statistics, before full unicode and before partitioning, row level binary logs, fractional seconds in temporal types and before EXPLAIN for INSERT/UPDATE/DELETE (which we still don’t have). There was a long way to go before MySQL would …

In this post I go into some performance metrics and time spent on using MySQL Enterprise Backup instead of mysqldump, and seeing how far I could go with some parallel configuration.

Setup:

It’s on an old laptop:

–Ubuntu 12.04 LTS, 32bit Intel Pentium M 1.86Ghz, 2Gb –Source disk:  internal 80Gb ATA ST9808211A –Destination:  external 1Tb SAMSUNG HD103SI –MySQL Enterprise Edition 5.6.15 –MySQL Enterprise Backup 3.9.0 –Employees sample database duplicated via MySQL Utilities 1.3.6 (on Win7 PC) to generate a ~5Gb MySQL Server. And to simulate data size, I used the MySQL Utilities:

mysqldbcopy --source=root:pass@host:3356 --destination=root:pass@host:3356 employees:employees1 \
employees:employees2 employees:employees3 employees:employees4 ... employees:employees18 \
employees:employees19 employees:employees20

…

In this post I go into some performance metrics and time spent on using MySQL Enterprise Backup instead of mysqldump, and seeing how far I could go with some parallel configuration.

Setup:

It’s on an old laptop:

–Ubuntu 12.04 LTS, 32bit Intel Pentium M 1.86Ghz, 2Gb –Source disk:  internal 80Gb ATA ST9808211A –Destination:  external 1Tb SAMSUNG HD103SI –MySQL Enterprise Edition 5.6.15 –MySQL Enterprise Backup 3.9.0 –Employees sample database duplicated via MySQL Utilities 1.3.6 (on Win7 PC) to generate a ~5Gb MySQL Server. And to simulate data size, I used the MySQL Utilities:

mysqldbcopy --source=root:pass@host:3356 --destination=root:pass@host:3356 employees:employees1 \
employees:employees2 employees:employees3 employees:employees4 ... employees:employees18 \
employees:employees19 employees:employees20

…

I recently wrote a post on tracking metadata locks (MDL) in MySQL 5.7, and I wanted to take a moment to expand on it by explaining a couple of the associated variables in more detail.

First off, once you have enabled the performance_schema *and* the metadata lock instrumentation, you can verify it with:

mysql> SELECT * FROM performance_schema.setup_instruments
    -> WHERE NAME = 'wait/lock/metadata/sql/mdl';
+----------------------------+---------+-------+
| NAME                       | ENABLED | TIMED |
+----------------------------+---------+-------+
| wait/lock/metadata/sql/mdl | YES     | YES   |
+----------------------------+---------+-------+

“ENABLED” will report “YES” if it is enabled properly, and “NO” if not.

“TIMED” (referring to event timing) reports “YES” if it was enabled via the my.cnf or my.ini file, and it reports …

At FOSDEM 2014 ProxySQL and MaxScale were both presented. Both are proxy that can help build sophisticated MariaDB/MySQL architectures. But currently what is the most used proxy with MySQL? It is HAproxy. HAproxy is a level 4 proxy that has no knowledge of the MySQL protocol. Being low level makes it very fast but it [...]