Enable MyISAM Auto-Repair

MyISAM can be configured to check and repair its tables automatically. By enabling the MyISAM auto repair you let the server check each MyISAM table when it is opened. It checks  if the table was closed properly when it was  last used, also checks if it needs any repair, if required it repairs the table.

To enable auto check and repair,you can start the server with –myisam-recover with following options.

DEFAULT for the default checking.

BACKUP tells the server to make a backup of any table that it must change.

FORCE causes table recovery to be performed even if it would cause the loss of more than one row of data.

QUICK performs quick recovery: Tables that have no holes resulting from deletes or updates are skipped.

You can also add it to the my.cnf file as shown below

[mysqld]

myisam-recover=FORCE,BACKUP

-Thanks …

I've been using MySQL Enterprise Monitor for some time now and have seen it grow from a somewhat clunky (ALPHA version) to a scalable and robust monitoring system. The MySQL Enterprise Monitor makes my job easier in a number of ways. Below is a short list of what I love about MySQL Enterprise Monitor:

1. Tunable, agent based monitoring
2. Historic RRD graphs
3. MySQL Query Analyzer
4. Replication topology visualization
   

MySQL Enterprise Monitor was highlighted during "MySQL Sunday" at the Oracle Open World conference this past month. Given the ease of implementation and helpful GUI tools, MySQLEnterprise Monitor provides almost instant benefits for any MySQL shop.

Check out the full article …

I’ve written a tool to profile a process’s IO usage. It works by gathering lsof and strace from a process, and then figuring out how the file descriptors, function calls, and filenames are all related to each other. The manual page has examples. I’m curious to see how it works for you. Note that it might be a good idea to run this on your development or staging system before you go running it against your production MySQL server — there are rumors of strace misbehaving on some kernels.

Related posts:

1. How to find per-process I/O statistics on Linux
2. iopp: a tool …

“NoSQL”, for lack of better name, is a generic term that describes any data management system that does not use SQL as a query interface.  Generally this means any data management system that is non-relational, but the term also has also been stretched as far to include the boundaries of what constitutes a data management system at all (such as Hadoop).

Early on (a couple of years back in NoSQL time) when the term was coined I think the positioning was much more aggressive, but more recently this has been softened so now NoSQL is commonly quoted as meaning of “Not only SQL” or “next generation databases” (whatever that means).  The common message you get now is something along the lines of NoSQL systems are more “specialized”, each being designed to solve a smaller number of problems than the …

One... *billion* emails!

One *Billion* Emails

In email marketing there are senders of all shapes and sizes, from small businesses using self-serve ESPs to the largest web properties self-sending to massive user bases. While only a few senders will reach or exceed volumes of one billion messages per month, the tools and practices needed to achieve such a volume level are applicable to all senders who want to succeed in email marketing.

Who Am I?

My name is Mike Hillyer (click here for bio and social links). I manage a team of Sales Engineers for Message Systems, a leading provider of digital messaging solutions for both senders and receivers. In my work over the last several years I have helped a number of …

Hi All,

I am going through some of the sessions for IOUG’s Collaborate 2011 Conference and trying to fill in slots for the bootcamp, and while we have some great sessions we could use a few more sessions. Specifically I would love to get a couple of sessions on a few the following topics:

• InnoDB in General
• InnoDB Internals & scalability
• General Overview of available Storage Engines (Pros/Cons)
• MySQL options for Very Large databases ( ala Partitioning, Sharding )
• MySQL Monitoring Options
• NDB Cluster

These are just a few suggestions, please feel free to submit any topic thats related to MySQL…  even if its not a fit for the bootcamp, there is a MySQL track that it would fit into.  IOUG extended the MySQL Deadline until next Monday for us, so let’s get some more papers in!  You can submit …

Last Tuesday I read the post from Dave where he encouraged people to give drizzle a shot. It got me thinking “why on earth have I not tried it before?” and so Wednesday night, having the options of watching criminal minds or dexter on tv or compiling drizzle, i figured, lets do the right thing for once and get on with it.

I must say, I was not too eager to compile a new tool but the guys at drizzle have done a good job (at least as regards Ubuntu (Lucid) since thats where I installed it) at documenting what is needed. I only needed to improvise a couple of times but that was it.

So here go the commands I used:

sudo apt-get install -y python-software-properties
sudo add-apt-repository ppa:drizzle-developers/ppa
sudo …

UPDATE: An on-demand replay for the webinar discussed below is available here:
http://mysql.com/news-and-events/on-demand-webinars/display-od-572.html

And there is a new whitepaper for MySQL Replication posted here:
http://mysql.com/why-mysql/white-papers/mysql-wp-replication.php

The recent announcement of the MySQL 5.5 Release Candidate included some pretty staggering increases in performance and scalability. 

Replication is also an area where many enhancements have been made including semi-synchronous replication, replication heartbeating, fsync tuning, relay log recovery, per-server replication filtering, etc.

On Tuesday 12th October, Dr. Lars Thalmann who leads the engineering team responsible for the development and implementation of these …

Warning, the following is quite ugly, but does the job :)

A while back I needed to create an archive slave database from a half a terabyte myisam master and had space restrictions. I could not dump the db, load it, then drop keys (archive doesn’t support keys apart from a primary key on one column as of 5.1), alter engine etc (would take even longer than it took either way). So an ugly single liner came to mind and worked nicely too.

mysqldump -uuser -ppassword -h127.0.0.1 -P3306 dbname --master-data=1 | sed 's/ENGINE=MyISAM/ENGINE=archive/g' | grep -v '^ UNIQUE KEY' | grep -v '^ KEY' | perl -p0777i -e 's/,\n^\)/\n\)/mg' | mysql -uuser -ppassword -h127.0.0.1 -P3307 dbname

So what is it doing?
Broken down:
mysqldump -uuser -ppassword -h127.0.0.1 -P3306 dbname --master-data=1 –> extract the database with the master position
sed …

The MySQL IN() Comparison Operator is said to be very quick if all the values are constants (the values are then evaluated and sorted first, and the search is done using a binary search). However, what if the field which the IN clause refers to, is part of the index used to execute the query? […]