So today Roman, one of the developers on the Doctrine project, pointed me to an article that was discussing the misuse of DISTINCT. This article went so far as to say that "A SELECT DISTINCT query is frequently a "code smell". The article pointed to another article hosted at onlamp.com. That author was advocating the use of subqueries to more efficiently filter out redundant rows. Immediately I began to wonder if this is really a feasible approach since MySQL's subquery handling is very slow. I could imagine this being faster on RDBMS where the subquery implementation is more mature. That being said comments in the onlamp.com article point to the fact that even on Oracle things get slower with the …

One of the most frequently needed functionality in the MySQL Proxy is the need to know which server you are on. This is not given, on purpose, by the proxy, because the proxy is supposed to be transparent. It is not supposed to matter which back-end server you are on.

However, for testing purposes we often want to know which back-end server we’re on. Thus I developed functionality for SHOW PROXY BACKEND [INDEX ADDRESS OTHER].

SHOW PROXY BACKEND INDEX — gives the index of the server you’re on (backend_ndx, ie 1)

SHOW PROXY BACKEND ADDRESS — gives the address of the server you’re on (ie, foo.bar.com:3306)

SHOW PROXY BACKEND OTHER — gives the address of all the other servers except those you’re not on, in multiline format.

Note that I was pretty lazy and the commands are case-sensitive. But I figured that since this is supposed to be used …

I need help from my fellow mysql users.  I know some of the people who read this are alot better then me with mysql so hopefully you can help

So today we decided that we are going to migrate one of our master database servers to new hardware.  Since we got the hardware this morning and we wanted to move on to it asap, we decided that we will take our slave down, copy data from it, and bring it up on future master server.  At that point, we will let it run as slave to the current master server until its time for us to take it down.  Reason we did that instead of mysqldump/import was to avoid the lag mysqldump creates on our server.

After we did all this and put up the new master server, we started to notice odd issues.  After looking around and comparing old db with new, we found out that new db was missing data.  How it happened is beyond me and is the reason why I am writing this.  …

Let me prefix this post by stating that I’m a developer and not a business analyst, but I wanted to point out something that strikes me as a bit contradictory. In recent posts like these by Savio Rodrigues and Matt Asay, there are references that say the commercial plugins MySQL/Sun was planning on releasing were part of an OSS business model. While the plugins would have been tied to an OSS project, the products themselves would have been commercial*. I think these products (and other current products MySQL/Sun offers only as closed source) should actually be considered as commercial product offerings (under a commercial business model), and not associated with a pure OSS business model. To me (and some may disagree) an …

It is that time of the year when many PostgreSQL fans gather in Ottawa, Canada for PGCon 2008 next week. This will be my first visit to PGCon in Ottawa. Earlier this year I had presented two sessions "PostgreSQL and Benchmarks" and "Best Practices of PostgreSQL on Solaris" at PostgreSQL Conference 2008 East in Maryland. Thanks to that visit, this time I might recognize many people by face this time around.

Sun is a Gold Sponsor at PGCon 2008. There will be quite a bit of presence from Sun in PGCon. Josh, Max, Robert, Magne, Zdenek, Jim, Mayuresh et all will be present out there.

Josh Berkus is doing a tutorial on  "GUCs: A Three Hour Tour" on …

The 97th edition of Log Buffer, the weekly review of database blogs, has been published on Brian “Krow” Aker’s Idle Thoughts.

We have Jeff Smith and Ward Pond standing by for two upcoming editions. And if you’d like to contribute, make yourself known in the DBA community-at-large (and have some fun in the process), you too can do Log Buffer! Read the homepage and send me, the Log Buffer coordinator, an email.

And now, Brian …

Welcome to the 97th week of Log Buffer. I am Brian Aker, and I will be your cruise director :)

Synchronisation in via scripting in the Database? Jonathan Lewis has a write up on making use of a locking package for Oracle. How about some published release notes for Oracle 10gR2?

On the MySQL side we have a post about "Time Delayed Replication", or what I often refer to as "we break our databases a lot, so we would like some more length in the rope please".

Ever seen a DBA run through a data center in the hopes to …

EnterpriseDB is sponsoring a survey to track which open-source databases people use. Make your voice heard: Vote today. It takes less than 30 seconds to answer, and covers such questions as why you use an open-source database, with which operating system do you use it, etc.

During my morning reading, I happened upon this verse from Ecclesiastes:

1 To every thing there is a season, and a time to every purpose under the heaven:...

2 a time to plant, and a time to pluck up that which is planted....

It made me think of the ongoing debate around open-source business models (illustrated well in a recent post by Savio and perhaps more so in the comments section to that post), kicked up by MySQL's recent decision to offer closed extensions to its core (100 percent open source) database, but one that has been simmering for a long time. MySQL is essentially saying, "We've spent a decade planting. We'd like to reap a little of what we've sown …

I have thought about putting up forums on my blog for LONG time and even thought about writing my own. But after playing with phpBB3 for a while on my other site (http://totalplaystation.com/forum), I have decided to use it instead. Let’s just face it; I don’t have the time or resources to write all of the functionality phpbb3 provides. Isn’t it a big reason why we all love open source?

If any of the phpbb guys read this, Thank you and keep up the good work!

Check out the forums: http://crazytoon.com/forum/ and feel free to post  questions, comments, suggestions, rants, etc.