When you rely on something like Jenkins to help manage your project, if you don't have a feature regularly tested in it, that feature often bitrots pretty quickly. This was the case for our Windows compile of libdrizzle. It worked months ago, but then some folks tried it recently and, well - not so much with the working. That meant I had to do three things this weekend:

1. Get the Windows machine that was sitting at my old office powered off and actually plug it in in my new office
2. Fix the build
3. Connect that machine to Jenkins

I'm happy to report all three are done, and we now have a Jenkins slave building libdrizzle on every push. I believe I should also be able to build the client programs, so I'll add them soon - and then it's only a few steps away from having Jenkins produce an msi or something that people can download.

In case you're wondering, we …

I’ve done it before, and I’m sure many others have.  You type:

SELECT * FROM t1,t2;

Without any conditions, and then just wait as your console spews out every combination of the two tables possible in what is called an implicit cartesian join.  Worst still when you are hosting and one of your client’s apps does this (I’ve seen this too many moons ago).

So, in Drizzle trunk today and in our RC release next week we have a new error “Implicit cartesian join attempted.” which will fire every time you try a query such as the one above.  If you really want a full cartesian join without a WHERE or ON condition (sometimes, it is needed) then you can use the CROSS keyword.  For example:

SELECT * FROM t1 CROSS JOIN t2;

…

Giuseppe has a great post about the Evolution of MySQL metadata, and I thought I’d have a look at what we have in Drizzle. It’s pretty easy to work out how many tables are in each schema, we just query the standard INFORMATION_SCHEMA.TABLES view:

drizzle> select table_schema,count(table_name)
    ->  from information_schema.tables
    -> group by table_schema;
+--------------------+-------------------+
| table_schema       | count(table_name) |
+--------------------+-------------------+
| DATA_DICTIONARY    |                53 |
| INFORMATION_SCHEMA |                20 |
+--------------------+-------------------+
2 rows in set (0 sec)

In Drizzle it’s important to note that there is a differentiation between SQL …

If you execute the following, what does your RDBMS do?

CREATE TABLE t1 (a int);
START TRANSACTION;
INSERT INTO t1 (a) VALUES (1);
START TRANSACTION;
INSERT INTO t1 (a) VALUES (2);
ROLLBACK;
SELECT * FROM t1;

The answer may surprise you.

So, what is all this dbqp / steve_austin mess?
Short answer – it is a nascent test runner.  Currently it duplicates the functionality of test-run.pl, but it is implemented in what I hope to be a more adaptable and reusable manner.  Please note that I said ‘duplicate’.  We haven’t touched test-run.pl or changed anything about how that tool works.  We don’t want to shoot ourselves in the foot by breaking a currently useful tool.

steve_austin…really?
Yes, it is test-run.pl, but better…stronger…faster ; )

dbqp?
database quality platform.  The idea is that this isn’t meant to just run a single type of test.  The code is intended to facilitate the execution of other tests.

Why?
Let me give …

Virtual IP addresses or VIPs are commonly used to enable database high availability.   A standard failover design uses an active/passive DBMS server pair connected by replication and watched by a cluster manager.  The active database listens on a virtual IP address; applications use it for database connections instead of the normal host IP address. Should the active database fail, the cluster manager promotes the passive database server and shifts the floating IP address to the newly promoted host.  Application connections break and then reconnect to the VIP again, which points them to the new database.

Virtual IP addresses are enticing …

Drizzle supports one character set (unless you include binary) which is UTF8.  It is the character set used by most of the web and supporting many different character sets can lead to complications.  That is not to say that there are not advantages of supporting many different types of character sets like MySQL does, but more care is needed when using them.

As an example of this, a new Drizzle user came online today saying that drizzledump’s MySQL to Drizzle conversion was turning ‘è’ to ‘è’.  When drizzledump connects to a MySQL server it sets the connection to UTF8 so that the dump output is compatible with Drizzle.  After a bit of discussion it was discovered that the user’s table was latin1 and connection was latin1 (PHP does this by default) but they were storing and retrieving UTF8 data. …

On Thursday January 27th at 10am PST I will doing a webinar on Tungsten Replicator together with my colleague Giuseppe Maxia.  The title is "What MySQL Replication Cannot Do.  And How to Get Around It."  Basically it is a nuts and bolts description of Tungsten Replicator capabilities like multi-master replication, failover, parallel apply, and using replication for zero-downtime upgrade.  If you have ever wanted an in-depth look at the Tungsten Replicator this is a good opportunity. 

During 2010 we implemented an amazing number of new replication features ranging from pipelines early in the year to fast disk logs, multiple replication services per process, bi-directional replication, and parallel apply by the end.  We will be building out all of …

In case you missed it here, we are very proud to announce that Drizzle’s transaction log is passing all of our tests.  For quite some time, David Shrewsbury, Stewart Smith, and Joe Daly have been putting a lot of love into the log code.  Please don’t be fooled by Dave’s praise of QA now that the storm has passed…you should have heard the names he called me and the things he plotted when we were rooting these bugs out ; )  However, now that there is a permanent record of his words, I’ll be reminding him about this post the next time my testing becomes a pain in his posterior and I feel him giving me the stink-eye in IRC (heheh)

With that said, we really have been putting tons of …

Way back in 2008 (which is a long time ago in Drizzle’s history) Zak Greant created a logo for the Drizzle project (as seen above).  For some reason which has been lost through the ages we switched from this to using the rain cloud logo which was part of the Tango project.

After a lot of discussion it was found that most of us preferred the old logo, not only does it actually have the name in it but in my opinion it is more stylish than the rain cloud.  As a result we have switched back to the old logo and are making this the official Drizzle logo.  We will be rolling it out over the various Drizzle related sites shortly.

It is licensed under a …