I explored two interesting topics today while learning more about Postgres.

Partial page writes

PostgreSQL’s partial page write protection is configured by the following setting, which defaults to “on”:

full_page_writes (boolean)

When this parameter is on, the PostgreSQL server writes the entire content of each disk page to WAL during the first modification of that page after a checkpoint… Storing the full page image guarantees that the page can be correctly restored, but at a price in increasing the amount of data that must be written to WAL. (Because WAL replay always starts from a checkpoint, it is sufficient to do this during the first change of each page after a checkpoint. Therefore, one way to reduce the cost of full-page writes is to increase the checkpoint interval parameters.)

Trying to reduce the cost of full-page writes by increasing the checkpoint interval highlights a compromise. …

News Monday!

Matt Asay to JOIN Canonical as COO

This took me a bit by surprise at first. I don't find myself often agreeing with Matt. Most of what he tends to write/argue for is what I have referred to in the past as "crippleware". Canonical in recent time has taken to opening up their platform. I've been a strong advocate for Launchpad, it is a great service. I love that they opened it up in recent time. When it comes to infrastructure software on the size of LP, I don't believe that many others will ever install it. Slash, G-Forge, and the Livejournal software are examples of infrastructure software that approach the size or outweigh the LP codebase. They have rarely been successfully deployed by others. The advantage in the Launchpad software being open source is the …

We have been using tpcc-mysql benchmark for long time, and there many results published in our blog, but that's just single workload. That's why we are looking into different benchmarks, and one
of them is TPCE. Yasufumi made some efforts to make TPCE working with MySQL, and we are making it available for public consideration.

You can download it from our Lauchpad Percona-tools project, it's
bzr branch lp:~percona-dev/perconatools/tpcemysql

Important DISCLAIMER:
Using this package you should agree with TPC-E License Agreement,
which in human words is:

• You can't name results as "TPC Benchmark Results"
• You can't compare results with results published on http://www.tpc.org/ and you can't pretend the …

If you have multiple database servers with strange names, or if you have to hop over multiple machines to connect to any mysql database server, then you know what a pain it can be to administer such a setup. Thanks to some scripting, you can automate such tasks as follows:

Create an expect script:
/path/to/sshmysql.exp

#!/usr/bin/expect -f
#script by darren cassar
#mysqlpreacher.com

set machine [lindex $argv 0]

set timeout -1

spawn ssh username@$machine
match_max 100000
expect -exact “assword: “
send — “password\r”
send — “sudo -k; sudo su – mysql\r”
expect -exact “sudo -k; sudo su – mysql”
expect -exact “assword:”
send — “password\r”
interact

# you should change the word password in ‘send — “password\r”‘ to your login password
# if you have the same password for each …

One of the issues I have with the Free Software approach is that advocates have habit of throwing the baby out with the bathwater when discussing issues that they see as in any way negative to free software.

I was reminded of this while reading Bradley M. Kuhn’s criticism of Mark Shuttleworth’s reported views on copyright assignment.

Having read the original interview with Mark, and then Bradley’s response, it is pretty clear that the two have very different perspectives on copyright assignment: Mark is speaking from the perspective of a commercial business, Bradley form that of a non-profit foundation.

The two entities have very different reasons for enforcing copyright assignment …

Ken Jacobs has been a fantastic advocate of the Oracle and MySQL user communites.  I met Ken on the board of the Independent Oracle Users Group (IOUG).  While Ken was the board liasson on the IOUG board, he was always supporting the Oracle user groups and made very important contributions throughout his time on the board and afterwards.  After serving time on the board, Ken was still always

Are you tired of manually renaming MySQL tables, one by one, especially when dealing with a large number of them? In this guide, we’ll introduce you to a MySQL stored…

The post How to bulk rename table MySQL first appeared on Change Is Inevitable.

Yesterday a friend came across an oracle query problem: Consider below table: cid cname.... cdata 1 x xxxx 1 x xxxx .. 2 xzzz fjnd 3 a evddd Now the…

The post Oracle query-eliminate duplicate but one using rowid first appeared on Change Is Inevitable.

What does it take for someone, fiercely loyal to a company to suddenly leave? Ken Jakobs, Oracle employee number 18, a man that sincerely loves the company, has resigned! The only reason I can think of is an extreme snub!

I must say, I am very disappointed. The prospect of Ken running MySQL was a light at the end of the tunnel for the community. Why? Because Ken is a MySQL insider! He knows the project, he knows the community.

As an engine developer I have come to know Ken well over the last 4 years. He lead the InnoDB team and is largely responsible for the improvements made to the engine since the Oracle acquisition. At the yearly Engine Summit he was always professional and constructive in his suggestions, with a deep technical knowledge of the subject. His track record shows that he has always kept his word with regard to Oracle's …

This post explains how to compile oursql and install it on MacOS 10.6. oursql is a Python database interface for MySQL, an alternative to MySQL for Python (i.e. MySQLdb) and MySQL Connector/Python.

First, find out which MySQL you installed. This can be either the 32-bit or the 64-bit version. To make sure, find the mysqld (e.g. in /usr/local/mysql/bin) and do the following in a Terminal window:

shell> file /usr/local/mysql/bin/mysqld
.../mysqld: Mach-O 64-bit executable x86_64

If you see x86_64, you got 64-bit, otherwise 32-bit. If you see both, then you have a universal build. This is …