There were so many valuable articles already written by others over past years explaining all details about InnoDB transaction isolation modes and how to deal with this. So, I'll avoid to repeat what was already said ;-) -- my attention attracted the performance study made by PeterZ and published in the following article: http://www.percona.com/blog/2015/01/14/mysql-performance-implications-of-innodb-isolation-modes/ -- the article is very good and providing a good analyze of the observed problem which is solved by using READ-COMMITTED transaction isolation instead of REPEATABLE-READ (which is default in InnoDB).. The natural question is coming then: why don't we have then the READ-COMMITTED mode by default?.. Is there any danger?..

Let's then investigate together..

First of all, you should …

MySQL meets NoSQL with JSON UDF

I recently got back from FOSDEM, in Brussels, Belgium. While I was there I got to see a great talk by Sveta Smirnova, about her MySQL 5.7 Labs release JSON UDF functions. It is important to note that while the UDF come in a 5.7 release it is absolutely possible to compile and use the UDF with earlier versions of MySQL because the UDF interface has not changed for a long time. However, the UDF should still be considered alpha/preview level of quality and should not be used in production yet! For this example I am using Percona Server 5.6 with the UDF.

That being said, the proof-of-concept that I’m about to present here uses only one JSON function (JSON_EXTRACT) and it has worked well enough in my testing to present my idea here. The JSON functions will probably be GA sometime soon anyway, and this is a useful test of the JSON_EXTRACT function. …

Within the MySQL data directory, the InnoDB storage engine creates two types of files — the data files and the redo log files. Each data file (or ibd file) belongs to exactly one tablespace. Each tablespace is given a unique identifier called the space_id. One tablespace can have 1 or more data files. If a tablespace has more than one data file, then the data files have a specific order or sequence. The data files can be thought of as being concatenated to each other in that specific order.

The data file is made up of a series of equal sized pages. Each page in the data file is given a unique number identifier called the page number (page_no). The first page of the first ibd file is given the page_no of 0. The page number of the first page of the second ibd file of the tablespace is …

Taxonomy upgrade extras: MySQL Enterprise Monitormonitoringeventhandlermpmperformance monitor

MySQL Enterprise Monitor (MEM) has by default no Event Handlers created and activated. These Event Handlers you have to define yourself according to your needs.

In this article we discuss how to create MySQL Enterprise Monitor Event …

What kinds of aliveness/health checks should we build into Nagios? Which metrics should we monitor with thresholds to raise alarms, and what should the thresholds be? What graphs should we build of status counters, which graphs should we examine and what do they mean?

In this webinar, Baron Schwartz answers these database monitoring questions and more.

If you did not have a chance to join the webinar, the slide deck is embedded below. You can also register for a recording here.

[…] I am connecting following Andrews advice: Stackoverflow Link Also, Monitoring and Managing […]

First things first: I could use this title for every year, it is an evergreen. In order for this title to make sense, there must be a specific context and in this case the context is Big Data. We have seen new ideas and many announcements in 2014, and in 2015 those ideas will shape up and early versions of innovative products will start flourishing. Like many other people, I prepared some comments and opinions to post back in early January then, soon after the season’s break, I started flying around the world and the daily routine kept me away from the blog for some time. So, as a good last blogger, it may be time for me to post my own predictions, for the joy of my usual 25 readers. Small Data, Big Data, Any Data The term Big Data is often misused. Many different architectures, objectives, projects and issues deviate from its initial meaning. Everything today seems to be “Big Data” – whether you collect structured or …

This Log Buffer Edition sheds light at some of the nifty blog post of the week from Oracle, SQL Server and MySQL.

Oracle:

Patch Set Update: Hyperion Data Relationship Management 11.1.2.3.504

The Hitchhiker’s Guide to the EXPLAIN PLAN Part 33: The mother of all SQL antipatterns?

MongoDB as a Glassfish Security Realm

E-Business Suite customers must ensure that their database remains on a level that is covered by Error Correction Support (ECS)

…

This Log Buffer Edition spread love of databases just before Valentine’s Day. Lovely blog posts from Oracle, SQL Server and MySQL are here for you to love.

Oracle:

Creating a Mobile-Optimized REST API Using Oracle Service Bus by Steven Davelaar.

GROUP BY – wrong results in 12.1.0.2

Using Edition-Based Redefinition to Bypass Those Pesky Triggers

It’s easy to make mistakes, or overlook defects, when constructing parallel queries – especially …

One of the interesting challenges in writing a system like VividCortex is writing a query digesting algorithm that deals with all of the technology-specific features, bugs, and quirks. When we added PostgreSQL performance monitoring recently, I knew this would be a new challenge because Postgres uses ANSI standard syntax for quoted strings, but MySQL uses different syntax. After checking a bit further, I also found something I didn’t know about: PostgreSQL also supports a nonstandard quoting syntax, which is called “dollar quoting.”

There are other interesting considerations about query digesting, so I thought it was worth a blog post.

Digesting queries is a huge issue. Because VividCortex digests similar SQL statements together, identifying literals accurately is important. If we think something is a literal and it’s an object name, we’ll group …