Hi,annamalai

I think there is a little wrong in section "Hidden Fields of a InnoDB Table":

...For all InnoDB tables, 3 fields are internally added to the table – DB_ROW_ID, DB_TRX_ID and DB_ROLL_PTR...

Based on my knowledge, i think DB_TRX_ID and DB_ROLL_PTR must be added to the table, but DB_ROW_ID is not,this field is only added when the table has neither primary key nor unique key. Am i right?

Thanks for a great description. I thought that ROW_ID was only used for tables without an explicit PK?

Percona is glad to announce the release of Percona Server 5.1.66-14.2 on January 15th, 2013 (Downloads are available here and from the Percona Software Repositories).

Based on MySQL 5.1.66, including all the bug fixes in it, Percona Server 5.1.66-14.2 is now the current stable release in the 5.1 series. All of Percona‘s software is open-source and free, all the details of the release can be found in the 5.1.66-14.2 milestone at Launchpad.

New Features:

…

nice. I assume that the new read only transaction support also dramatically improves READ COMMITTED performance since a new read view is created for each statement in isolation levels lower than repeatable read.

The MariaDB Java Client 1.1.0 has been released. You can download it here.

This version focused on fixing all known database metadata bugs and ConnnectorJ incompatibilities. Specific fixes include:

• Consistent, compatible with ConnectorJ handling of JDBC catalogs vs schemas vs databases
• Implementation of several missing methods in DatabaseMetaData
• Better handling of statement timeouts
• OSGi-specific entries have been added to MANIFEST.MF so it can be used in OSGi environments
• Added support for dumpQueriesOnException=true in the JDBC URL
• Added support for IPv6 addresses in the connector
• Added SSL support
• and more…

See the Release Notes and …

Update: Recording!

Finally, the end of year madness is over and we’re in a fresh new year. That must mean it’s time to get back into #DBHangops! Tune in on Wednesday, 1/16/13 at 5:00pm PST to get in on the fun and share your experiences.

Check back on this blog post tomorrow or check this twitter search to grab the link to join the Google Hangout.

Topics for this weeks hangout include:
* triggers: maintenance, problems, etc.
* Oracle MySQL utilities (similar to Percona toolkit)
** Slideshow of MySQL utilities
* Database caching and cache expiration
* InnoDB log file size
** …

One of the most common causes of a poor Sphinx search performance I find our customers face is misuse of search filters. In this article I will cover how Sphinx attributes (which are normally used for filtering) work, when they are a good idea to use and what to do when they are not, but you still want to take advantage of otherwise superb Sphinx performance.

The Problem

While Sphinx is great for full text search, you can certainly go beyond full text search, but before you go there, it is a good idea to make sure you’re doing it the right way.

In Sphinx, columns are basically one of two kinds:

a) full text
b) attributes

Speaking in MySQL terms, Full text columns are always indexed and using the very …

I saw a post on profiling memory usage today and this reminds me of several discussions I have had with different people.

Why would you want to profile the memory usage? Usually to see where memory is allocated and for what purposes, and usually you only care when memory usage is higher than expected. That is a DBA normally wants to use all available memory on a server for mysqld, whatever that size may be.

Configuration parameters may be inappropriate and need adjusting, so having a way to determine the range of memory usage based on those parameters would be most helpful.  However, the configuration parameters as a whole put no limit on memory used, so different workloads can quite easily lead to memory being insufficient on the OS, triggering swapping or perhaps the …

Lenka and I are at Oracle HQ for the Oracle Leadership Summit. This event is the start of the calendar year for us and brings the leaders of Oracle user groups together to share information. From around the world, leaders of IOUG, OHUG, and other groups to share ideas. The concept used by the Boston MySQL User Group with MySQL Marinate has caught the attention of quite a few folks. The vast majority of IOUG folks also run MySQL in their data centers and they are interested in seeing local MySQL Groups flourish.

So if you are interested in starting a new MySQL Users Group, let me or Lenka know AND contact your local IOUG chapter. We can aid you in getting meeting space in an Oracle office and your local IOUG chapter can help with other organizational issues when startinga group.

And be sure to say ‘hi’ at the Rocky Mountain Oracle Users Group Training …

We wanted to take a moment to say thanks to all of our customers and to the wider MySQL and MariaDB community. Today we announced a doubling of our customer base for the year ending December 31, 2012. Significant milestones over the last year included new technology and service partnerships, several awards, rapid hiring, as well as three upgrades to TokuDB®. We even dabbled in some MongoDB benchmarks. And to fuel continued growth in 2013, we secured additional venture capital funding last November.

Did You Hear? NASA Uses TokuDB for Big Data with MySQL!

To read the full press release and learn more, see here. To get started with TokuDB, …