The latest from the MySQL community

Now as new MySQL Storage engine - Falcon is public I can write down my thought about its design, which I previously should have kept private as I partially got them while working for MySQL.

These thought base on my understanding, reading docs, speaking to Jim, Monty, Arjen and other people so I might miss something, something might be planned to be changed or not 100% correct but anyway you might find it interesting.

In many cases what I find good or bad would base of my MySQL use with existing applications - if you design new applications which are done specially for Falcon you might find those aspects positive.

[-] No Spinlocks Falcon does not use Spinlocks. It has its own lock implementation which does operation system wait if resource is unavailable. We’ll see where this leads us but I believe on multiple CPU systems you need some spinning done, at least for some types of locks where conflicts will …

Or should I say, the MySQL MiniConf at linux.conf.au.

There are some great talks - just check out the schedule & abstracts.

But what’s most interesting, in my opinion, is the cool Answer Guys feature. Think of it like stumping the expert, a little. The MySQL Support Team presents Arjen Lentz (MySQL trainer too!), and Morgan Tocker, for your answering pleasure, all MiniConf day.

They’ll be by the lawn (I’m not sure how UNSW is setup), thats definitely very near the room we’re having the MiniConf at (Room 6).

MuleSource Adds New VP of Engineering to Executive Team, MuleSource (Press Release)

Eclipse Joins Java Community Process, eWeek, Steve J. Vaghan-Nichols (Article)

Qlusters CTO on the Datacenter Revolution, LinuxInsider, Jack Germain (Article)

Should Apple Open Up the iPhone?, Red Herring, Falguni Bhuta (Article)

Red Hat’s JBoss revenue edges toward …

I mentioned when grant statements take into effect in Sql Server, MySql, and Oracle here.

I found out recently that there are some implementation differences when you grant only delete permission on a table to a user. MySql and Sql Server do this the same way, whereas Oracle is different.

Suppose you have:

1. Table t1: create table t1 (c1 int);
2. User TestLogin. The only permission of this TestLogin is delete on t1.

In all 3 database platforms, TestLogin can find out what columns t1 has by default, using either

desc t1

or

sp_columns t1

In both Sql Server and MySql, the only thing you can do is:

delete from t1;

which essentially wipes out the whole table. You can do the same thing in Oracle.

However, if you do:

…

We’re looking to implement CJK Support in Open Source Full Text search engine Sphinx .
Initially we’re thinking to base search ob bi-gram indexing to keep it simple, especially as according to research papers it offers decent quality for most cases. This is not that complex to implement however there is no way we can test it as we have zero knowledge of Chinese or Japanese.

If you know Chinese Japanese or Korean and would like us help us testing Sphinx support for these languages let us know. No special development skills are required. If you’re reading this blog you should be technical enough.

After some time here is another post concerning MySQL. It is not as if I had not had anything to do with MySQL in the meantime, but most of it was mailing back and forth with their customer support (which is really quite good) to get some issues resolved we stumbled over in our MySQL 4.1 to 5.0 migration.

Before those were fixed we could not use MySQL 5 with our application, because there were some incompatible changes we could not work around.

One of them was the unsatisfactory precision when querying DECIMALs I wrote about earlier. This is fixed in 5.0.32-enterprise and the just released 5.0.33 community edition (see Bug #23260). In fact I was just about to write about the new release policy which I find somewhat strange (enterprise and community editions with the …

After some time here is another post concerning MySQL. It is not as if I had not had anything to do with MySQL in the meantime, but most of it was mailing back and forth with their customer support (which is really quite good) to get some issues resolved we stumbled over in our MySQL 4.1 to 5.0 migration.

Before those were fixed we could not use MySQL 5 with our application, because there were some incompatible changes we could not work around.

One of them was the unsatisfactory precision when querying DECIMALs I wrote about earlier. This is fixed in 5.0.32-enterprise and the just released 5.0.33 community edition (see Bug #23260). In fact I was just about to write about the new release policy which I find somewhat strange (enterprise and community editions with the …

It happens sometimes, when I report a bug, that I have an argument with someone at the receiving end of the reporting chain. The raw happens over the definition of a bug. For instance, there is a new implementation of a consolidated tool. The new tool does almost all the old one did, except X. Therefore I file a bug report saying that X is missing. The ensuing argument runs along the lines of:
- This is not a bug, says the Verifier. You can't say it's a bug because it does not do what you want. It should be downgraded to feature request.
- This is the recommended replacement of the old tool, I retort, and as such it should do at least what the old tool did, plus the new stuff. I insist it is a bug.
- The manual does not mention feature X for the new tool, and then it is not a bug. It's a feature request"
The Verifier's reasoning is technically correct, and it is within the boundaries of his allowed action, so I see no point …

This article explains how to create a fixed-size FIFO (first-in, first-out) queue in SQL, where rows added after a threshold will cause the oldest row to be deleted. There are several ways to do this, but MERGE on Oracle and DB2, and MySQL's non-standard extensions to SQL, make an elegant solution easy.

Goal:

Getting rid of filesorts and temporary tables by tuning MySQL queries.

Background:

Filesorts and temp tables are a necessary evil in MySQL, used when MySQL must sort the data before returning the output to the user. They are the most common issue with slow queries in MySQL, the main reason being that if the output is too large, you can kiss goodbye in-memory performance, and say hello to disk access.

Common User and Manager symptoms:

1. Sore throats due to excessive swearing at poor database performance.
2. Sore hip pockets due to lack of scalability requiring continuous hardware purchases.
3. Sore users who are sitting on high speed bandwidth and have to wait more than 1.5 secs for a response from any web page. Google has raised the bar, time to ditch the straddle technique and go for the Fosbury Flop.

Appropriate Medicine:

The quickest way to …