Both Oracle and MySQL provide a number of sample schemas so users can build different schema environments and load them with data. So I thought I'd get one of the Oracle sample schemas and go through the exercise of converting it to a MySQL schema. I could have gone in either direction, since this is more of a MySQL blog I made MySQL the destination. Before I start let me introduce some of

I had written about this but mostly in parts. Here is a step by step guide to optimizing mysql. Following variables should be looked into for optimizing mysql.Memory consumption: Total memory consumption should be less than the available RAM. You should also leave a small amount of memory for the OS. Total memory consumption can be calculated using this formula (for myisam tables):Key_buffer + (

In an earlier post, the pursuit of openness, I announced that MySQL is working at a new release model.

There are still a few details to sort out, but the general plan is ready. The new release model has been approved and starts to operate immediately.

The basic principles of this model are:

• The trunk is always at least in beta quality.
• A milestone starts in beta quality ( never in alpha) with a merge between the trunk and a stage tree;
• Milestone releases, with RC quality, released every three to six months.
• Integration windows between milestones allow the insertion of new features from stage trees
• GA releases happen every 12 to 18 months;
• There are not more than two releases in active …

In an earlier post, the pursuit of openness, I announced that MySQL is working at a new release model.

There are still a few details to sort out, but the general plan is ready. The new release model has been approved and starts to operate immediately.

The basic principles of this model are:

• The trunk is always at least in beta quality.
• A milestone starts in beta quality ( never in alpha) with a merge between the trunk and a stage tree;
• Milestone releases, with RC quality, released every three to six months.
• Integration windows between milestones allow the insertion of new features from stage trees
• GA releases happen every 12 to 18 months;
• There are not more than two releases in active …

MySQL clients uses COM_* commands to communicate with the MySQL server. MySQL show status breaks these commands into many categories and displays how many times each of these commands were executed. It, however, does not display the time taken to processes those commands as well as how many times the command execution resulted in an error. Enter Dtrace

I wrote a small DTrace script to figure out what commands(COM_*) are being executed on the server and summarize them. If you have used truss -c on Solaris before, you must liked its concise summary; I have tried to present the output in a similar fashion.

For Sysbench read-write (10 queries per transaction) test with 1 thread, each executing 1 transaction, you see

# ./cmdtruss
Sampling... Hit Ctrl-C to end.
^C
Command                  seconds     calls  errors
Query                      0.042         2        
Quit                       0.000         2        
CloseStmt …

Image via Wikipedia

Todd Hoff has posted a link to a Los Alamos National Lab presentation on Graph Databases.  In this paper they provide a revisit on the classic RDBMS vs Graph database debate.

The Relational Database hasn’t maintained its dominance out of dumb luck.  Instead the RDBMS has consistently outperformed while providing the most general use capability of all the variety of platforms that have been available.  Many other approaches have been tried, often these have provided better object model integration (OODBMS) or better data model representation.  But when the …

Articles on this blog have been pretty scanty of late for a simple reason--we have been 100% heads-down in Tungsten code since the recent MySQL Conference. The result has been a number of excellent improvements that are already in Subversion and will appear as open source builds over the next couple of weeks.

Tungsten has a simple goal: create highly available, performant database clusters using unaltered commodity databases that are simple to manage and look as close to a single database as possible for applications. Over the last two months we completed the integration of individual Tungsten components necessary to make this happen.

Full integration is a big step forward and finally gets us to the ease-of-use we were seeking. Imagine you want to add a slave database to the cluster. …

Hi All!

I was just reading PlanetMySQL and noticed Mike Hillyer's recent post on a user-friendly age function for MySQL. Basically, this function accepts two DATETIME values and returns an indication of the time between the two dates in the form of a human-readable string. For example:

mysql> select  TimeDiffUnits('2001-05-01', '2002-01-01')
+-------------------------------------------+
| TimeDiffUnits('2001-05-01', '2002-01-01') |
+-------------------------------------------+
| 8 Months                                  |
+-------------------------------------------+
1 row in set (0.00 sec)

Just for fun, I decided to try and refactor it, and I'm …

In addition to being practical, …

Here is a bit of code I worked up for us a recently for Drizzle:

drizzle> DELIMITER |
Note that there is no semicolon after the '|' symbol, which we will use as the delimiter for our purposes. You have to choose a delimiter that does not appear in your procedure, and it can be more than one character.

drizzle> CREATE PROCEDURE perl_hello (param1 string)
-> return "Hello " . $_[0] . "!"
-> |
Query OK, 0 rows affected (0.05 sec)

drizzle> CALL perl_hello('Brian');
-> |
Query OK, 1 row affected (0.00 sec)

drizzle> DELIMITER ;
drizzle> SELECT @perl\G
*************************** 1. row ***************************
@perl: Hello Brian!
1 row in set (0.00 sec)


Stored Procedures!?!

In an actual language!?!

About a week ago I was talking to a CTO for a …