We had an absolutely rocking July this year when we inducted new college graduates (NCGs) into the MySQL team at Oracle, Bangalore.
There were fun themes and games that went hand-in-hand with the training program bringing about a vibrant atmosphere that gave the NCGs a chance to prove that they are indeed a great addition to this high energy MySQL team here in Bangalore :).
The fun part of the induction spanned five Tuesdays and culminated with the grand finale in which we were bowled over by some brilliant performances by the NCGs. What I loved about these Tuesdays was that it jump started the induction programme bringing about some great team building and a very informal introduction to our MySQL team.
On the first Tuesday, the NCGs who were expecting a conventional welcome party were in for a surprise as they were asked to put up an impromptu talent show. After the initial inhibitions and reluctance, they came out with …

This post focuses on the problem of the InnoDB log sequence number being in the future.

Preface: What is an InnoDB log sequence number?

The Log sequence number (LSN) is an important database parameter used by InnoDB in many places.
The most important use is for crash recovery and buffer pool purge control.

Internally, the InnoDB LSN counter never goes backward.
And, when InnoDB writes 50 bytes to the redo logs, the LSN increases by 50 bytes.
As such we can count LSN in megabytes, gigabytes and etc.

Now for the problem: LSN being in the future!

When you have set innodb_force_recovery like this:

innodb_force_recovery=6

and then issue a data affecting query.

For example, if you are dropping a corrupted table after doing a mysqldump for backup …

Tuesday, 10 September 2013Author: colincharles

The MariaDB Server has a long history that is worth chronicling. It began life humbly as just another storage engine. While many were concerned when InnoBase, the makers of InnoDB were acquired by Oracle, MySQL AB still had a plan: acquire Netfrastructure, makers of the now defunct Falcon storage engine and allow Michael “Monty” Widenius to assemble a high calibre team of his choice to create a new transactional storage engine called Maria. Both teams worked even through the Sun acquisition, however Monty decided that MySQL 5.1 was released with much too many bugs that he wanted fixed. It didn’t take long to cement the decision that Monty would leave Sun Microsystems because barely two months passed and Oracle had proposed the acquisition of Sun Microsystems, thus gobbling up the MySQL team too!

Monty looking for a drinking partner in Lisbon

…

The next meetup for the MySQL User Group NL is on September 12

Details and signup: http://www.meetup.com/MySQL-User-Group-NL/events/97461512/

Introduction For a long time MySQL server supported only one trigger for every action (INSERT, UPDATE, DELETE) and timing (BEFORE or AFTER). In other words, there could be at most one trigger for every pair (action, timing). It means that a user couldn't assign for example two BEFORE INSERT triggers for the same table t1. To workaround this restriction and allow several actions to fire on some table event, a user had to implement several stored procedures (one for each activity that would be implemented as independent trigger), create trigger for a table and call this stored procedures from the trigger. As of MySQL 5.7.2 this limitation has been removed. It means that starting the MySQL 5.7.2 a user can create for example, two BEFORE INSERT triggers, three AFTER INSERT triggers and four BEFORE UPDATE triggers for table t1. And this triggers will be called in the prescribed order determined (in generally) by the sequence in which triggers …

Hello,

I am Shivji Kumar Jha (shiv), a graduate from BIT Mesra who fell in love with MySQL sometime ago. I am one of those lucky ones who got to work at MySQL as well and I thoroughly enjoy the experience every single day. I believe this is the golden age of technology and I aim to  contribute my bit to it affecting millions of people through an open source software – the most popular open source database on web – MySQL ! At MySQL I am currently working as a software developer with the replication team, which provides high-availability solution built into MySQL server. My area of expertise revolves around analyzing and enhancing performance Database replicas, enhancing the replication monitoring tools. This blog is an attempt to reach out to people and share the tiny details I know about MySQL Replication. The views expressed on this blog are my own and do NOT necessarily …

In talking to existing MongoDB users and TokuMX evaluators, I’ve often heard that the performance of MongoDB is very good as long as your working data set fits in RAM. The story continues that if your working data set grows to be larger than the RAM on your server, the built-in sharding capabilities of MongoDB allow you to scale horizontally.

As my benchmarking presentation at Percona Live 2013 pointed out, I’m never one to accept something without at least running it once myself. I decided to run my Sysbench for MongoDB benchmark on an in-memory workload, meaning that all of the data fits …

MySQL Tech Day @Paris

We're happy to announce you that MySQL Tech Day will take place in Paris on Oct 10, 2013 in Oracle main office. It'll be a full day event giving you an occasion to listen directly from Oracle developers about most of the improvements made recently within MySQL 5.6 and 5.7 development.

One of MySQL’s continued values is to be easy to use. A key part of this, is making sure the default configuration is kept up to date and safe for everyone.

Internally, these configuration changes are made in close cooperation between our engineering and support teams, who are in the best position to provide insight into customer impact.

For MySQL 5.6, hats off to James Day who led the project internally. Taken directly from James’ blog, here is the list of changes made:

From my testing MySQL Cluster on the Raspberry Pi’s I thought I’d share this little extract, just in case someone tries the same, some day.. somewhere.. why? I don’t know.

Ok, so when we pull the plug on one of the pi’s, we have of each component falling down, but because one of them is the arbitrator (node-id=2) then cluster falls over.

Before the ‘accident’:

  ndb_mgm -e show

Connected to Management Server at: localhost:1186
Cluster Configuration
———————
[ndbd(NDB)]     2 node(s)
id=3    @10.0.0.6  (mysql-5.5.25 ndb-7.3.0, Nodegroup: 0, Master)
id=4    @10.0.0.7  (mysql-5.5.25 ndb-7.3.0, Nodegroup: 0)

[ndb_mgmd(MGM)] 2 node(s)
id=1    @10.0.0.6  (mysql-5.5.25 ndb-7.3.0)
id=2    @10.0.0.7  (mysql-5.5.25 ndb-7.3.0) …