Abstract: Heating up the InnoDB Buffer Pool during the MySQL instance startup should significantly improve InnoDB Performance in the beginning of the life of the Instance. This is achieved by sequential scans of the needed data instead of random I/O reads which would happen when we just let the system work it out by itself.

How to find the database objects which can be loaded during MySQL start-up and how to load them automatically is described in this article.

New Table in the INFORMATION_SCHEMA

Some of my colleagues have already described methods on how to heat up a Slave after its startup. [1, 2, …

Once again this week, you are holding the new edition of Log Buffer in your hands. From across the database planet, fresh and sizzling blog posts of Oracle, SQL Server and MySQL are presented just for you in Log Buffer #230. Enjoy and give your feedback in the comments. Oracle: Have you ever wondered about [...]

There are two sections for rows in the page format for InnoDB compressed tables. The compressed section has one or more rows and must be decompressed to access individual rows. The modification log has uncompressed rows and rows can be accessed without decompressing. The modification log is used to avoid decompressing and then possibly recompressing the compressed section on every row change. The buffer pool also has separate uncompressed copies of some pages so that every row read does not require a page decompression.

I want to understand when a page must be decompressed or recompressed. This is definitely an incomplete list.

• A page is decompressed when a row is read and the uncompressed version of the page is not in the buffer pool.
• I think a row can be deleted from the compressed section …

When I spoke at Percona Live (video here) on running an E-commerce database in Amazon EC2, I briefly talked about using RAID 10 for additional performance and fault tolerance when using EBS volumes. At first, this seems counter intuitive. Amazon has a robust infrastructure, EBS volumes run on RAIDed hardware, and are mirrored in multiple availability zones. So, why bother? Today, I was reminded of just how important it is. Please note that all my performance statistics are based on direct experience running a MySQL database on a m2.4xlarge instance and not on some random bonnie or orion benchmark. I have those graphs floating around on my hard drive in glorious 3D and, while interesting, they do not necessarily reflect real-life performance.

Why? …

Back in February I wrote an article titled A Small Fix For mysql-agent. Since then we did a few more fixes to the agent and included a Bytes Behind Master (or BBM) chart. For those who can't wait to get their hands on the code, here's the current version: MySQL SNMP agent RPM. For those who'd like to learn about it's capabilities and issues, keep reading.

What to Expect From this Version
The article I quoted above pretty much describes the main differences with the original project, but we went further with the changes while still relying on Masterzen's code for the data collection piece.

The first big change is that we transformed Masterzen's code into a Perl module, …

And another video from OpenDBCamp is online....Today it is from Henrik Ingo - "Buildbot & EC2: how to qa and package your db product".

I cannot seem to find the slides Henrik used, but the video is now online at http://www.youtube.com/watch?v=07tsdSvR5C0.

By the way, there are plans to video *all* of the sessions at OSCon Data next week (MySQL and otherwise), which is what made me look in my "video to do" folder earlier this week and realize that I had not yet put up all the OpenDBCamp videos yet!

[Update]As can be read on Mac OS X Hints here, this setting also applies to the side bar in Mail.[/Update]

Apple has - as was to be expected - slightly modified the appearance of many Mac OS X controls in 10.7 "Lion". Some of those changes have caused protest and debate around the net, but I believe this is just the same as it is with face-lifted car designs, which means in a few weeks everyone will have gotten used to the new style and consider the previous version old-fashioned.

However, there is one particular little issue that I could tell I would not come to like immediately: The icons - and more importantly the font-size - in the Finder's left hand sidebar is way bigger than it was in Snow Leopard. This makes the source list look much more cluttered in my opinion.

At first, I headed for the …

I'm pleased to announce the release of Spider storage engine version 2.26(beta) and Vertical Partitioning storage engine version 0.15(beta).
Spider is a Storage Engine for database sharding.
http://spiderformysql.com/
Vertical Partitioning is a Storage Engine for vertical partitioning for a table.
http://launchpad.net/vpformysql

Recently, I can't upload the binary file to Launchpad, so I put the binary file at the following. Please use the following for downloading binary file.
http://spiderformysql.com/download_spider.html

The main changes in this version are following.
Spider
- Add table parameter "active_link_count", "read_only_mode", "first_read" and "second_read".
- …

Abstract: It is common practice in MySQL table design that fields are declared as NOT NULL but some non-sense DEFAULT values are specified for unknown field contents. In this article we show why this behavior is non optimal an why you should better declare a field to allow NULL values and use NULL values instead of some dummy values.

What we can see often out in the field

Recently we had a discussion with a customer if it makes more sense to store a default value or NULL in InnoDB tables when we do not know the value of the field yet. About this 8 byte DATETIME field we were discussing:

CREATE TABLE test (
  ...
, dt DATETIME NOT NULL DEFAULT '0000-00-00 00:00:00'
  ...

The customer mentioned, that he is mostly storing nothing in this field which in fact results in '0000-00-00 00:00:00' occupying 8 bytes. …

After long days I’m writing this post. Though my blog is very popular for facebook related tutorials, but this is not anything related to facebook or php. This is about me and beginning of my career.

I think every programmer should learn different languages and work in different platforms. You can ask me why? If you work on PHP backend development for 5 years, you will become an experienced guy and will earn better income.

So why you’ll invest your time for other language and other platform?
Because it will give you a good taste of programming and you’ll enjoy yourself. I’m not telling you to leave PHP development and move to other platform, I’m just telling you to make some extra time from your regular job and work in different platform or technology.

In my student life I learned and worked on the following …