On Thursday 12th September I co-presented a webinar on how MySQL Cluster delivers the key benefits of NoSQL Data Stores without having to give up the features that people rely on from relational databases (consistency, SQL etc.). There was a particular focus on how to use the new node.js JavaScript API which was recently released as part of MySQL Cluster 7.3. If you weren’t able to attend the live event then the webinar replay is available here. If you scroll down to the bottom of this post you’ll see a summary of the Questions and Answers from the session.

The new MySQL JavaScript Connector for Node.js is designed to deliver simplicity and high performance for JavaScript users.

Enables end-to-end JavaScript development, from the …

Not registered yet for MySQL Connect? Time is running out, Register Now if you want to save US$300 over the onsite price.

We'll have 6 Birds-of-a-Feather sessions at the conference. They offer you the opportunity to engage in lively, passionate and insightful discussions, as well as to influence the MySQL roadmap.

They will take place on Saturday from 5.30pm to 6.30pm, you will therefore be able to continue some of the discussions during the following MySQL Connect reception starting at 6.30pm.

The BoFs this year include:

MySQL Sharding, Replication, and HA
Imperial Ballroom A …

One type of question we get very often (even in the form of filed bugs!) is how to switch from stock MySQL to Percona Server or switch from Percona Server 5.5 to Percona XtraDB Cluster using yum, but à la apt-get, i.e. having yum handle the replace.

In its simplest form, yum cannot replace a package¹ for another like apt-get does:

# yum -q -q install Percona-XtraDB-Cluster-server
Error: Percona-XtraDB-Cluster-server conflicts with Percona-Server-server-55
Error: Percona-XtraDB-Cluster-client conflicts with Percona-Server-client-55
Error: Percona-XtraDB-Cluster-shared conflicts with Percona-Server-shared-55


One solution for this is to manually uninstall …

Sreekar,
Since the file is being written as a single stream, even if you designate multiple threads, in effect it will take the same amount of the time since it will wait to synchronize the output in the order it needs to be written.
Most SBT enabled backup frameworks like OSB, Symantec and TSM expect there data to be written from a single thread.
-Sanjay

So folks, bit short notice I know, but i’ll be talking at LAMP stack event tomorrow in London. Loads of interesting stuff about MySQL and the other pieces of the LAMP Stack. You can register here:

http://www.oracle.com/us/dm/17128-emeafm13045970mpp005-oem-1989140.html

Agenda is below..

September 17, 2013 By Severalnines

Galera cluster has known limitations, one of them is that it uses cluster-wide optimistic locking. This may cause some transactions to rollback. With an increasing number of writeable masters, the transaction rollback rate may increase, especially if there is write contention on the same dataset. It is of course possible to retry the transaction and perhaps it will COMMIT in the retries, but this will add to the transaction latency. However, some designs are deadlock prone, e.g sequence tables. In this blog we present how you can minimize the risk for deadlocks due to the design of Galera. 

Test Case

Here is a simple test case. We have a table that contains a column and a row that hold a number and is regularly updated to provide …

In my third year of engineering I decided to take coding very seriously and started solving questions at codechef  and my first question I solved there was titled "Life, the Universe and Everything"  , the story is somewhat similar with blogging also, I think this is the time to take it very seriously.

So here I am starting a blog, and to have some motivation I keep the title of this post as Life, the Universe and everything :D .

Well little about me, I am a software developer by profession and  currently working in MySQL.

In this blog I will talk about the features I am working on, and also about the cool stuff happening in this N00B tech world.

So just to remind you before you start thinking that this is just another blog in the oceans of tech …

MySQL 5.6 ships with a default config file that sets the SQL mode to NO_ENGINE_SUBSTITUTION,STRICT_TRANS_TABLES . Here is what happens if you try to insert NULL values into a table with NOT NULL columns:

mysql> create table safetyfirst(
    -> id int primary key not null auto_increment,
    -> country varchar(60) NOT NULL,
    -> product varchar(60) NOT NULL );
Query OK, 0 rows affected (0.24 sec)

mysql> insert into safetyfirst(country) values('Sweden');
ERROR 1364 (HY000): Field 'product' doesn't have a default value

If someone tells you that MySQL 5.6 by default allows you to do this, ask them to prove it using the default settings we use for new installations and check their claim by asking them for the output of SHOW VARIABLES LIKE 'sql%'; .

We would like to use NO_ZERO_DATE, NO_ZERO_IN_DATE, …

And that's a wrap! Check out the recording:

Hello!

Coming up this Wednesday, September 18th, 2013 at 12:00pm pacific (19:00 GMT) come and join #DBHangOps to discuss:

• Data warehousing in MySQL
  • Shipping large tables from production to your Data warehouse
  • Do you use Federated engine?
  • What other solutions do you use?
• Answer some questions about MySQL-isms (requested by Tim Callaghan)
  • Why does MySQL have FRM files instead of storing them in a data dictionary table?
  • Why doesn't InnoDB support other page sizes?
  • Why do we store data in a master.info file?
• What are you excited to see at MySQLConnect?

As always, take a look at …

The plug-able storage engine architecture is a design feature that is really separates MySQL/MariaDB from the pack. This feature allows for running the storage engine, or engines that best meet your table's needs. Choosing the right storage engine for your needs can make a huge impact on the performance of your database, but like many things in MySQL there can sometimes be too many options available to make the right choice clear.

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