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 …

Up until a short while ago I was still using local.xml for modifications to a project-specific theme, even though 1.9 introduced the theme.xml file. The scenario I encountered which forced me to ditch local.xml is pretty interesting and made me understand the need for the theme.xml layout updates.

Basically, I was working on a website that now wanted to expand in a different country. The new store looked similar, but would have slightly different templates. Usually - in a similar situation - I would use a different theme under the same package (to make use of the “natural” theme fallback to “default”).

I couldn't use a different theme in this case because I was already using themes for certain pages that looked slightly different as a way to easily override template files without having to write any XML. (I was changing the theme in an observer event for specific pages.)

Then I tried using a new package. But that …

Just under a year ago on my old blog I discussed and even demoed the new Linux live kernel patching solutions. I was reviewing these technologies out of my own curiosity as well as HP's Advanced Technology Group having an interest. I think these technologies are great, I am personally more of a fan of the user experience of RedHat's kpatch solution but any solution is a great technical achievement.

Having said this I believe that the use case for this technology is quite narrow. Last time I looked into these technologies only patches that affected the code of functions could be modified. Changing structs and data definitely didn't work and I suspect that changing function declarations was also dangerous. There is also a performance …