The Mysqlnd replication and load balancing plugin alpha release has focused on laying foundations for read-write splitting and load balancing. Thus, we can now look into more juicy topics such as support of schemata based partitioning to increase the granularity of load balancing. Not every slave server needs to replicate all schemata (databases) and tables of the master. The plugin load balancer shall be aware of it and transparently pick the server which has the entities required to execute a statement. Some brainstorming…

Lesson for the week: If you really want to stir up an anthill, attack the conventional wisdom of code development best practices.

In other news ...

Another piece of Sun falls off the good ship Oracle

At this point, I could almost follow the practice of Gregg Easterbrook 's Tuesday Morning Quarterback and put this text on Autotext, but in the past week, Oracle cast off another piece of their acquired Sun technology. In this case, it was the integrated build platform "Hudson." Either fed up with the infighting that had led to the spin-off "Jenkins" project, or simply …

I’ve recently been blogging about how partitioning is a poor man’s answer to covering indexes. I got the following comment from Jaimie Sirovich:

“There are many environments where you could end up creating N! indices to cover queries for queries against lots of dimensions.”

[Just a note: this is only one of several points he made. I just wanted to dig into this one in some detail. Here goes...]

Although it is, in theory, possible to generate a workload that would take N! indexes, this is not a realistic (or useful) bound (leaving aside that this workload would kill partitioning!). For one thing, it would take N! queries to exercise all those indexes. And the queries would have to include every field in the where clause — as we’ll get into below.

So what is a reasonable bound on the number of covering indexes that …

If you happen to be around at this years LinuxTag 2011 in Berlin/Germany, you are invited to attend my short talk on MariaDB as a drop-in replacement for MySQL. The talk focusses on differences between MySQL Community Edition and MariaDB … Weiterlesen →

Infobright and InnoDB AMI images are now available

There are now demonstration AMI images for Shard-Query. Each image comes pre-loaded with the data used in the previous Shard-Query blog post. The data in the each image is split into 20 “shards”. This blog post will refer to an EC2 instances as a node from here on out. Shard-Query is very flexible in it’s configuration, so you can use this sample database to spread processing over up to 20 nodes.

The Infobright Community Edition (ICE) images are available in 32 and 64 bit varieties. Due to memory requirements, the InnoDB versions are only available on 64 bit instances. MySQL will fail to start on a micro instance, simply decrease the values in the /etc/my.cnf file if you really want to try micro instances.

*EDIT*
The storage worker currently logs too much …

One of the more exciting new features in MySQL 5.6 is the InnoDB to Memcached interface. Basically memcached runs as a daemon plugin and can bypass the SQL optimizer and parser for NoSQL access.

The first step is to download the new MySQL 5.6 with the InnoDB-Memcache preview. Sorry, Linux only at this time. And install memcached.

Second, run the provided configuration script mysql> < scripts/innodb_memcached_config.sql. This will do a lot of the work to get things running out of the box and one of the links below details what is happening behind the scenes when you run the script. Third, load the plugin mysql> install plugin daemon_memcached soname “libmemcached.so”;. Forth, to make sure we can see recently inserted data, you will need to set the transaction level mysql> set session TRANSACTION ISOLATION LEVEL read uncommitted;

…

I'm pleased to announce the release of Spider storage engine version 2.25(beta) and Vertical Partitioning storage engine version 0.14(beta).
Spider is a Storage Engine for database sharding.
http://spiderformysql.com/
Vertical Partitioning is a Storage Engine for vertical partitioning for a table.
http://launchpad.net/vpformysql

The main changes in this version are following.
Spider
- Add table parameter "skip_default_condition" and "direct_order_limit".
- Add server parameter "spider_skip_default_condition" and "spider_direct_order_limit".
  "direct_order_limit" improves some SQL with "order by" and "limit" performance.
- Add UDF "spider_flush_table_mon_cache".
  "spider_flush_table_mon_cache" is used for reflecting changing of …

Yesterday I posted results from some MySQL benchmarks I had been doing on a large server. In this post I'd like to list 4 important fixes that were done to avoid bad performance:

read more

We have mostly finalized the Percona Live schedule at this point, and I thought I’d take a few minutes to introduce who’s going to be speaking and what they’ll cover. A brief explanation first: we’ve personally recruited the speakers, which is why it has been a slow process to finalize and get abstracts on the web. Sometimes you know someone’s a dynamite speaker and you discuss over the phone, and then it takes a long time to get a title and abstract from them. In many cases the better they are the busier they are, so this is expected.

Let me introduce just a few of the great speakers we have lined up for this event: Brendan Gregg, Dr. John Busch, and Vladimir Fedorkov.

Brendan Gregg

Brendan Gregg is the crazy guy who likes to scream at a chassis …

Permalink: http://bit.ly/RcRieg



Refer to part 1 for the rationale behind the code or you can skip to part 3 for a working example as well as how you can debug the stored procedure.

Important: The SP will create a table named `dynamic_cursor`. Make sure this table does not exist in the database where you will be storing the procedure. Here's the 1st iteration of a general purpose dynamic cursor:

DELIMITER $$
DROP PROCEDURE IF EXISTS `dynamicCursor` $$
CREATE DEFINER=`root`@`localhost` PROCEDURE `dynamicCursor`(
 IN selectStmt TEXT,
 IN whatAction VARCHAR(255),
 INOUT …