Tech.Bitez

Upgrading MySQL 4

Wasif — Fri, 08 Jan 2010 18:00:17 +0000

Today I found a couple of useful articles about upgrading MySQL 4. One is written by Peter Zaitsev and other by Guillaume Lefranc.

They are talking about problems you may face while upgrading as well as benefits of MySQL 5.

I hope you guys can really benefit from it.

MySQL 5.0.77 in RHEL 5/CentOS 5

Wasif — Wed, 14 Oct 2009 18:51:10 +0000

Red Hat Enterprise Linux 5 and CentOS 5 are now shipping MySQL 5.0.77 instead of MySQL 5.0.45 on security grounds.

This is moderate security release according to RHEL and CentOS.

MySQL for online applications – Webinar Series

Wasif — Sat, 15 Aug 2009 20:49:10 +0000

MySQL.com is conducting webinars on its usage in online applications. It is a series of 5 webinars i.e.

Part 1: Introduction to MySQL Scale Out and Replication Services
In the first installment we look at the basics for deploying MySQL for a scalable online application such as:

Choosing the right architecture
Scale Out - What, Why and How?
Using MySQL Replication Services
MySQL Solutions to help manage your high-growth business

North America -- Tuesday, August 18, 2009: 10:00 Pacific time / 1:00 Eastern time

EMEA -- Wednesday, August 26, 2009: 10:00 am European Central Time

PHP sessions across subdomains

Wasif — Thu, 21 Aug 2008 12:04:45 +0000

If you are facing problems sharing sessions across subdomains, use the following code before session_start().

ini_set ( 'session.cookie_domain', '.mysite.com' );

Replace mysite.com with your domain name.

PHP 4 is dead, last release of PHP 4!!!

Wasif — Fri, 08 Aug 2008 17:45:21 +0000

The last release of PHP 4 is now available for download on 7th of August 2008. PHP 4 has been serving the web sites since 2000.

Count number of words in a MySQL column

Wasif — Tue, 01 Jul 2008 17:36:15 +0000

It is a common requirement to count number of words in a column of a MySQL database table. But MySQL does not have any built in function to count number of words as it usually has for number of purposes.

But you can do it without it with a simple trick e.g. you have a column name and want to count number of words in it. This query will return number of words separated with space in a column

SELECT SUM( LENGTH(name) - LENGTH(REPLACE(name, ' ', ''))+1)
FROM table

If you want to count number of words separated by some other string for example comma (,) or semicolon (;), simply replace space with your required character.

MySQL GUI Tools

Wasif — Thu, 01 May 2008 10:31:45 +0000

I am creating a list of MySQL GUI (front end) tools. I hope you will contribute this list.

A wide variety of MySQL GUI tools are available in the market. Most of them are free but some are paid as well. We can divide GUIs in 2 categories i.e. desktop and web based applications. Here is the list of popular MySQL GUI tools I have heard of

Desktop Application
- MySQL Workbench
- Old official MySQL GUI Tools (Linux, Windows, Mac OSX)
- HeidiSQL
- dbForge Studio (requires .NET Framework 2.0, 3.0 or 3.5)
- Navicat (Linux, Windows, Mac OS X)
- SQLyog
- CocoaMySQL (Mac OS X)
- SQL-Front
- Toad for MySQL
- ACDB sql client - Supports MySQL and Oracle
- Aqua Data Studio (Linux, Windows, Mac OS X, Solaris)
- DreamCoder (Windows)
- DBACentral (Windows)
- SQL Manager (http://www.sqlmanager.net/de/products/mysql/manager)
- DatabaseSpy
Web Based Application
- phpMyAdmin
- MySQL Quick Admin

If you know any good GUI Tool, please let me know.

Should we use template engines in PHP?

Wasif — Thu, 01 May 2008 08:50:40 +0000

I came across this discussion today on pros and cons of using template engines in PHP.

child pid 2299 exit signal File size limit exceeded (25)

Wasif — Sun, 30 Mar 2008 15:30:44 +0000

Today I found that Apache on my server was very slow and a lot of child pid xxxx exit signal File size limit exceeded (25) errors in error_log.

I simply searched for large (2gb) log files and deleted them. Everything became normal.

Increasing file upload limit in PHP

Wasif — Fri, 14 Mar 2008 19:10:40 +0000

There are different options to increase file upload limit in PHP. First is changing PHP configuration file (php.ini) and restarting webserver or overwriting the php.ini value in .htacces (this option is available if you are running Apache).

There are 2 directives which affect upload limit i.e. upload_max_filesize and post_max_size.

Now we look at the first method. First you have to find out where the php.ini is. To find out the location, make a .php file containing only this code and place it in your webroot and point your browser to this file.

 phpinfo(); ?>

In the page output you can find Configuration File Path. Open this file and change the values for upload_max_filesize and post_max_size according to your requirement e.g. to set 10MB upload limit, the values will be
upload_max_filesize = 10M
post_max_size = 10M

After changing the values, save php.ini and restart the webserver. If you open up the above PHP file again, you'll see the updated values of upload_max_filesize and post_max_size.

In case you don't have access to php.ini (in shared hosting environment) or don't want to restart the webserver then the best option is to use .htaccess.

The syntax for .htaccess as follows
php_value upload_max_filesize 10M
php_value post_max_size 10M

Apache supports .htaccess. I am not sure if you can overwrite these settings in .htaccess with lighttpd.