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The MariaDB project is pleased to announce the immediate availability of MariaDB 10.1.5. This is a Beta release.

See the Release Notes and …

One of the challenges in storage engine design is random I/O during a write operation. In InnoDB, a table will have one clustered index and zero or more secondary indexes.  Each of these indexes is a B-tree.  When a record is inserted into a table, the record is first inserted into clustered index and then into each of the secondary indexes.  So, the resulting I/O operation will be randomly distributed across the disk.  The I/O pattern is similarly random for update and delete operations. To mitigate this problem, the InnoDB storage engine uses a special data structure called the change buffer (previously known as the insert buffer, which is while you will see ibuf and IBUF used in various internal names).

The change buffer is another B-tree, with the ability to hold the record of any secondary index.  It is also …

Next Wednesday (June 10) I’ll be co-presenting a webinar on using MySQL in the cloud for High Availability (HA). Joining me will be 451 Research analyst Jason Stamper and together we’ll talk about the realities of HA using MySQL in the cloud and how vendors are responding to changing application requirements with new developments that can enhance your deployment.

We’ll also present a comparison of available solutions along with key best practices you can follow for successfully attaining HA in the cloud with MySQL. The webinar is scheduled for June 10 at 10 a.m. Pacific. Register here.

Together we’ll cover:

• What do HA MySQL deployments in the cloud look like …

Percona is glad to announce the new release of Percona XtraDB Cluster 5.6 on June 3rd 2015. Binaries are available from downloads area or from our software repositories.

Based on Percona Server 5.6.24-72.2 including all the bug fixes in it, Galera Replicator 3.11, and on …

A quick question, which I’ve asked once before –

if you were an Oracle DBA, then learned MySQL, what do you wish you knew before you got started?

Also, what was helpful to you as you learned?  (Websites, #mysql on irc, documents, etc.)  What do you wish you had (or want to have now) if you are a DBA for both Oracle databases and MySQL databases?

Ie, what would be good to give an Oracle DBA who wants to start learning or supporting MySQL as well?  Please respond with comments here, or directly email me at ben-dot-krug-at-oracle-dot-com.

Thanks!

Some applications have a heavy write workload on a few records – for instance when incrementing a global counter: this is called a write hotspot. Because you cannot update the same row simultaneously from multiple threads, this can lead to performance degradation. When using Percona XtraDB Cluster (PXC), some users try to solve this specific issue by writing on multiple nodes at the same time. Good idea or bad idea? Read on!

Simultaneous writes on a standalone InnoDB server

Say you have these 3 transactions being run simultaneously (id is the primary key of the table):

# T1
UPDATE t SET ... WHERE id = 100
# T2
UPDATE t SET ... WHERE id = 100
# T3
UPDATE t SET ... WHERE id = 101

All transactions will require a row lock on the record they want to modify. So T3 can commit at the same time than T1 and/or T2, because it will …

In my previous post, I showed you a way to store tweets in MySQL, and then use Perl to automatically publish them on Twitter.

In this post, we will look at automatically sending a “thank you” to people who retweet your tweets — and we will be using Perl and MySQL again.

Just like in the first post, you will need to register your application with Twitter via apps.twitter.com, and obtain the following:

consumer_key
consumer_secret
access_token
access_token_secret

One caveat: Twitter has a rate limit on how often you may connect with your application — depending upon what you are trying to do. See the Rate Limiting and …

It seems these days if anyone knows anything about tuning InnoDB, it’s that you MUST tune your innodb_buffer_pool_size to 80% of your physical memory. This is such prolific tuning advice, it seems engrained in many a DBA’s mind.  The MySQL manual to this day refers to this rule, so who can blame the DBA?  The question is: does it makes sense?

What uses the memory on your server?

Before we question such advice, let’s consider what can take up RAM in a typical MySQL server in their broad categories.  This list isn’t necessarily complete, but I think it outlines the large areas a MySQL server could consume memory.

• OS Usage: Kernel, running processes, filesystem cache, etc.
• MySQL fixed usage: query cache, InnoDB …

Setting up a database backup is a primary task for database administrators and we see perl and shell scripts wrapped around few of the backup-tools in practice. With right tools…

The post Setup and configure MySQL backup using Holland and Xtrabackup first appeared on Change Is Inevitable.

MySQL 5.5.44 was recently released (it is the latest MySQL 5.5, is GA), and is available for download here:

http://dev.mysql.com/downloads/mysql/5.5.html

This release, similar to the last 5.5 release, is mostly uneventful.

There were 0 “Functionality Added or Changed” items this time, and just 15 overall bugs fixed.

Out of the 15 bugs, there were 5 InnoDB bugs (1 of which also spans partitioning), 1 security-related bug, 1 performance-related, and 3 additional potential crashing bugs. Here are the ones worth noting:

• InnoDB: An assertion was raised on shutdown due to XA PREPARE transactions holding explicit locks.
• InnoDB: Removal of a foreign key object from the data dictionary cache during error handling caused the server to exit.
• InnoDB: SHOW ENGINE …