April 20, 2014

Using CHAR keys for joins, how much is the overhead ?

I prefer to use Integers for joins whenever possible and today I worked with client which used character keys, in my opinion without a big need. I told them this is suboptimal but was challenged with rightful question about the difference. I did not know so I decided to benchmark. The results below are for […]

Integers in PHP, running with scissors, and portability

Until recently I thought that currently popular scripting languages, which mostly evolved over last 10 years or something, must allow for easier portability across different platforms compared to ye good olde C/C++. After all, their development started a few decades after C, so its notorious caveats are all well-known and should be easy to avoid […]

Why Index could refuse to work ?

Have you ever seen index which refused to be used even if there is every reason for it to work (from the glance view):

Why on the earth index would not be used you would think, even if MySQL is mentioning it in “possible keys” ? Should you try to force it ?

MySQL Prepared Statements

If you care about archiving best performance in your application using MySQL you should learn about prepared statements. These do not neccesary provide performance beneft but they may, they also have other benefits. As a quick introduction – before MySQL 4.1 there were only textual statements and textual protocol for data transfer – query was […]

INSERT ON DUPLICATE KEY UPDATE and summary counters.

INSERT … ON DUPLICATE KEY UPDATE is very powerful but often forgotten MySQL feature. It was introduced in MySQL 4.1 but I still constantly see people unaware of it. Myself I like this feature big deal because it is designed in truly MySQL style – very efficient solution for freqent task while keeping it beautiful […]

To pack or not to pack – MyISAM Key compression

MyISAM storage engine has key compression which makes its indexes much smaller, allowing better fit in caches and so improving performance dramatically. Actually packed indexes not a bit longer rows is frequent reason of MyISAM performing better than Innodb. In this article I’ll get in a bit more details about packed keys and performance implications […]

My Innodb Feature wishes

At Users Conference Heikki did good presentation about Innodb planned features. I did not see some of big and tiny wishes listed so I was making notes. Here is what I’d like to see Packed indexes. In many cases then difference in Performace with MyISAM and Innodb is huge for read only workload it is […]