Xaprb

It seems that a lot of people want to try to improve MySQL performance by focusing on server status counters and configuration variables. Looking at counters, and “tuning the server,” is better than nothing, but only barely. You care first and foremost about how long it takes to execute a query, not about how many of this-and-that the server performs or about how big or small this-and-that buffer is. What you really need is timing information.

You can use the slow query log to find timing information about queries, and then you can examine those queries with SHOW PROFILES to see the timing information about the query’s execution itself.

This concept is very simple and absolutely fundamental: if you care about time (and you do!), then measure and optimize time. But it’s so often overlooked or misunderstood.

The addition of SHOW PROFILES was a major step forward in the ability to optimize server and application performance. (Thanks Jeremy Cole!) As time passes and people upgrade their servers, it’s becoming more common to see it in production, which is an enormous help. Now that the differences between the Community and Enterprise versions of the server have been erased, it will be available in all future server versions, which is great news.

I’ve had several customers in the last week or so who need a way to verify that their application will work well after an upgrade. I’m seeking input on a new tool to help with MySQL upgrades. Please add comments, either here or on the bug report, or on the mailing list topic.

If someone wants to sponsor this work, that would also be welcomed.

One of the minor things I’ve noticed when I use Thunderbird on my IMAP accounts is that it doesn’t download IMAP messages until I click on them. Then I have to wait until I can see the message. I have heard that this is supposed to be fixed in Thunderbird 3, and I tried it but a lot of the extensions I need aren’t compatible with it.

Today I finally tried to search and find out more about the problem. Turns out I’m not alone — others have noticed that the setting to download message bodies for offline use doesn’t do what it’s supposed to.

Fortunately, there’s an extension for this. It’s called Sync On Arrival. So far, it’s working like a charm. The only thing I had to do was edit the install.rdf to increase the version number. It’s compatible with Thunderbird 2, even though it says it’s not.

Edit: see the comments for a way to do this with configuration alone, rather than an extension.