Two weeks ago I announced new maintenance release of JSON UDFs: 0.2.1. It not only contains bug fixes, how you can expect from a maintenance release, but also contains improvements in build and test scripts.

First improvement is the easier way to build JSON UDFs on Windows. In the first version building on Windows was a pane: you had to build PCRE library, copy four files to directories where Visual Studio can find them and only then build JSON functions themselves. Now you can build this way too, but only if you really wish.

By default cmake will create appropriate makefiles for bundled PCRE sources and for JSON functions. Only command you need to prepare sources is:

"C:\Program Files (x86)\CMake 2.8\bin\cmake.exe" -G "Visual Studio 11 Win64" . -DMYSQL_DIR="/path/to/mysql/installation"   

And then you can build functions:

devenv my_json_udf.sln …

Upgrading MySQL is easy…

Upgrading mysql to a newer version is very simple: just replace the binaries, and run:

# mysql_upgrade

watch the error log after restarting the service to check if any configuration parameter have to change because of renaming, deprecating etc. and after all it could be done in a few minutes.

…but not as easy as it seems at the first sight.

But this is not as easy if you want to be sure, that the upgrade won’t break anything. Well, on a big site like Kinja, I can ensure you: you want to check out all of the possible bad things which could happen.

So, you have to check out three different aspects of the upgraded system:

• The slave data consistency

• The query result consistency

• The systems overall performance

The upgrade process Slave data …

Use your MySQL expertise to analyze the strengths and weaknesses of MongoDB.

SPEAKER: Tim Callaghan, VP of Engineering at Tokutek
DATE: Tuesday, December 17th
TIME: 1pm ET
Register Now!

MongoDB is a popular NoSQL DBMS that shares the ease-of-use and quick setup that made MySQL famous. But is MongoDB really up to the job? Is it right for your applications? If you understand MySQL well, you know how database systems work.

Join Tim Callaghan, VP/Engineering at Tokutek as he recaps his and CEO of Continuent, Robert Hodges, session from 2013′s Percona Live London. Learn how to lean on your knowledge of topics like schema design, query optimization, indexing, sharding, and high availability to analyze the strengths and weaknesses of MongoDB. System design is all …

Within MySQL, there’s a piece called a storage engine that reads and writes to disk on your behalf when you execute a query. It controls the way that your data is stored on disk. With MySQL, you can change what storage engine you use, which is helpful since every engine has different advantages and downsides, and you can select which engine to use based on your workload. There are two main engines: MyISAM and InnoDB. MyISAM was the default engine before MySQL 5.5 and it’s been there since the beginning. It’s also not crash-proof, it doesn’t have foreign keys, and it’s not transactional. InnoDB, on the other hand, has all these features.

What happens if you use MyISAM

No Safety Belt

Grooveshark (a popular music site) in …

My December 4 webinar, “Geographical disaster recovery with  Percona Replication Manager (PRM),”  gave rise to a few questions. The recording of the webinar and the slides are available here, and I’ve answered the questions I didn’t have time to address below.

Q1: Hi, I was wondering if corosync will work in cloud environment. As far as I know it is hard to implement because of no support of unicast or multicast.

A1: Corosync supports the udpu transport since somewhere in the 1.3.0 branch. udpu stands for udp unicast and it works in AWS for instance. Most recent distribution are using 1.4.x so it is easy to find.

Q2: For token wouldn’t it …

December 10, 2013 By Severalnines

As a follow-up to the Webinar on Zero Downtime Schema Changes in Galera Cluster, we’ll now walk you through the detailed steps on how to update your schema. The two methods (TOI and RSU) have both their pros and cons, and given parameters like table size, indexes, key_buffer_size, disk speed, etc., it is possible to estimate the time taken for the schema to be upgraded. Also, please note that a schema change is non-transactional so it would not be possible to rollback the DDL if it fails midway. Therefore, it is always recommended to test the schema changes and ensure you have recoverable backups before performing this on your production clusters. 

This post examines the way DDL changes are propagated in Galera, and outlines the steps to upgrade the …

I was pleased to see Morgan’s announcement about a fix to an old problem of mine. In March 2012 I complained about MySQL verbosity during installation.

In MySQL 5.7.3, this behavior was changed. While the default is still as loud as it can, you can now add an option (log_error_verbosity) to send only errors to STDERR, which allows you to hide the output of mysql_install_db, and still get the errors, if they occur.

Well done!

However, the same obnoxious verbosity is also in MariaDB 10.0.x. Since I discussed this specific bug with a few MariaDB developers early in 2012, I was disappointed to see this same output when running mysql_install_db with MariaDB. Here’s the same appeal: MariaDB …

This is both hilarious and sad. The new MySQL 5.7 milestone release presents a new feature — replication filters are now dynamic. This is a great and long awaited feature, no doubt about it.

In short, for years MySQL slaves could filter the incoming stream of replication events based on the database or table name these events were applicable to. These filters were configured using the my.cnf file (or command-line), in particular with the following variables:

replicate_do_db
 replicate_ignore_db
 replicate_do_table
 replicate_ignore_table
 replicate_wild_do_table
 replicate_wild_ignore_table

Naturally, users wanted to be able to change the values of these options without having to restart the server. And eventually Davi Arnaut implemented it. MariaDB got it as a contribution back in version …

In some application scenarios (e.g. PHP applications) client connections have very short durations, maybe only executing a single query. This means that the time spent processing connects and disconnects can have a large impact on the overall performance.

In MySQL 5.6 we started working on optimizing the code handling connects and disconnects. And this work has accelerated in MySQL 5.7. In this blog post I will first show the results we have achieved and then describe what we have done to get them.

The results

The graph below shows a comparison of the most recent 5.5 and 5.6 releases as well as the 5.7.2 and 5.7.3 milestones. We measured the number of queries per second (QPS) where each client executes a single query (point select) before disconnecting. For each server version we also tested with both Performance Schema disabled and enabled. Details about server hardware and configuration settings used, …

MariaDB CONNECT Storage Engine allows to access heterogeneous datasourses. This includes various file formats. But this also includes ODBC accessible datasources The CONNECT Storage Engine ODBC table type allows to access SQLite, Excel, SQL Server or Oracle databases. Some nice features of the ODBC CONNECT table type are: - Auto discovery of table structure. This [...]