Dr Charles Bell and I recently presented a webinar on MySQL Utilities; there was a heavy focus on what you can acheive with them and how you should use them. In case you couldn’t attend or want to listen to some of the details again, the replay from that webinar is available here.

Abstract:

MySQL Utilities provide a collection of command-line utilities that are used for maintaining and administering MySQL databases, including:

• Admin Utilities (Clone, Copy, Compare, Diff, Export, Import)
• Replication Utilities (Setup, Configuration, Automated Slave Promotion)
• General Utilities (Disk Usage, Redundant Indexes, Search Meta Data)

Andrew Morgan and Chuck Bell will …

We are happy to announce a new release of XAMPP for all platforms! This is a minor release that fixes the following issues in both XAMPP versions:

1.8.2-1 version (PHP 5.4 based)

• Fix issue with RedHat-based Linux distros (i.e CentOS) in which the start script would fail to autodetect the distribution and start the servers.
• Create "mysql" user if it does not already exist on Linux. Now MySQL runs as "mysql" user by default.
• Change Apache and ProFTP users to "daemon" on Linux. The previous "nobody" user does not exist on some Linux distributions by default (i.e. CentOS).
• Fix Mercury Mail configuration on Windows.
• Fix XDebug issue on Windows. The previous module did not work with this PHP version.

1.8.3-0 version (PHP 5.5 based)

• Updated PHP to 5.5.1 version for Windows, OS X and Linux.
• Fix issue with RedHat-based Linux distros (i.e …

This Log Buffer Edition marvels at the ease, simplicity, and power of the database bloggers as they go about their adventures in the realms of Oracle, SQL Server, and MySQL.

Oracle:

The new Oracle Database 12c’s “Implicit Result Sets” (IRS) feature allows query results to be returned from a stored PL/SQL procedure (or a PL/SQL anonymous block) without requiring a special PHP code.

Ranka has been spending a lot of time on big data and its application, architecture, and processes.

Kashif Manzoor tells us how to use the new Clone Log Parser utility in Oracle E-Business Suite.

…

Recently a forum question [ 1 ] got my attention:

Is there any performance issue with Union?

I used union all sometime back and it was performance issue just to make an opinion that we should used union in query.

The question itself was not too interesting because the answer is easy: It depends. But I wanted to see if there was an improvement in this common problem over time in MySQL.

Test set-up

So I prepared a little test to simulate some of the possible scenarios:

CREATE TABLE `u` (
  `id` int(10) unsigned NOT NULL AUTO_INCREMENT,
  `a` int(10) unsigned DEFAULT NULL,
  `b` int(10) unsigned DEFAULT NULL,
  `c` int(10) unsigned DEFAULT NULL,
  `d` int(10) unsigned DEFAULT NULL,
  PRIMARY KEY (`id`),
  KEY `a` (`a`),
  KEY `b` (`b`),
  KEY `c` …

Hi Joe,

Thanks for pointing that out.

I’ve downloaded that tool and tested, but I confess that I found it heavier than other SQL tools I used previously.

Regardless, their free version also offers SSH tunnel to connect to your MySQL which is brilliant!

Thanks once again.

Recently, I have faced one interesting issue with Master(Active)-Master(Passive) replication (RBR + Triggers). Passive master was stopped due to “Duplicate Entry” error with update statement. It was something like this.

Last_Error: Error ‘Duplicate entry ‘29014131’ for key ‘PRIMARY” on query. Default database: ‘db’. Query: ‘UPDATE `db`.`tab1` SET `empid`=’103′, `name`=’Nilnandan’,  `address`=’India ‘, `postcode`=’D100′, `phone`=’878 515 7788’;

Interesting thing was , id (primary key column) was not updated in above update statement. Initially I was confused but when I check further, found that both servers has binglog_format = row and there are some triggers in “tab1” table which is inserting records into “tab2” (Another table).

After some investigation, found that “If under row-based replication the slave applied the triggers as …

Debugging a Production War Story

This is a presentation i made for the 2013 Flipkart BootCampers.

Its a production war story and how we went about debugging the root cause.

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Installing Apache2 With PHP5 And MySQL Support On Fedora 19 (LAMP)

LAMP is short for Linux, Apache, MySQL, PHP. This tutorial shows how you can install an Apache2 webserver on a Fedora 19 server with PHP5 support (mod_php) and MySQL support.

If we have InnoDB pages there are two ways to learn how many records they contain:

• PAGE_N_RECS field in the page header
• Count records while walking over the list of records from infimum to supremum

In some previous revision of the recovery tool a short summary was added to a dump which is produced by the constraints_parser.

But if a page is lost and page_parser hasn’t found it, all records from this page are lost. In other words per-page recovery statistics gives us little idea about whether or not a recovered table is complete.

To cover this flaw a new tool index_check is introduced in …