Usama Dar's Blog

My new book PostgreSQL Server Programming – 2nd Edition is now available on all major online retailers. This book will show you that PostgreSQL is so much more than a database server. In fact, ...

http://usamadar.com/2015/04/05/my-new-book-postgresql-server-programming/

I wrote this entry for planet postgreql back in 2008. I am posting it here again not to lose it. The details here are a bit out of date but some of them might still be relevant. Autovacuum, somet...

http://usamadar.com/2014/09/30/autovacum-internals-from-2008/

My new book Nginx Module Extension is now out on all major online retailers. You will find this as a one stop guide to getting familiar with nginx module system and how to install and configure H...

http://usamadar.com/2013/12/28/nginx-module-extension/

Losing your software user’s attention is a matter of seconds, or probably just one second. That is why you must strive very very hard to make sure the application has sub-second response times....

http://usamadar.com/2013/03/27/speed-of-thought-why-is-speed-the-killer-feature/

I have been confused about this for half a month until i figured this out. So what is Anti-Caching? And why is it needed? How is it different from the traditional buffer-pool system in all ...

http://usamadar.com/2013/03/02/anti-caching-a-better-way-to-do-memory-management-for-database-systems/

If you are using Mac OSX (i am on Lion)  and you just installed Oracle JDK / JRE 7  your Java applets in Chrome will stop working. You will basically be told Chrome does not support Java 7 on ...

http://usamadar.com/2012/11/02/cant-run-java-plugin-in-chrome-for-mac-osx-after-installing-oracle-jdk-7/

Since the use of multi-core computers / PCs is common these days, there are more and more parallel programming frameworks coming up. If you use Scala (or Java)  you might have used the AKA frame...

http://usamadar.com/2012/09/15/difference-between-multi-threading-and-parallel-programming/

If you want to write a custom Nginx module, Emiller’s guide is a very good starting point. This article is a wee bit long and you might want to get your hands dirty just to see a full program....

http://usamadar.com/2012/09/02/writing-a-custom-nginx-module/

I have seen too many web services (and done a few) where fault handing is not user friendly / graceful.  Most of the times the way people code the web services using annotations or using POJOs ...

http://usamadar.com/2012/08/17/error-handling-in-soap-web-services-the-right-way/

i just created a simple Library which provides some commonly used helper String functions which you will find useful when working with XML documents You can check it out on my gitHub profile here

http://usamadar.com/2012/07/25/simple-xml-library-for-java/

Based on different parameters, reuirements etc you have the following popular options. Block level replication – DRBD PostgreSQL Streaming replication (SR)– only available 9.0 + Slony Trigger...

http://usamadar.com/2012/07/17/postgresql-replication-options/

A bit complicated but worth reading http://docs.oracle.com/cd/E19957-01/806-3568/ncg_goldberg.html

http://usamadar.com/2012/07/15/what-every-computer-scientist-should-know-about-floating-point-arithmetic/

Your online businesses are ultimately only as profitable as they are accessible—if no one can find you online, your hard work in creating a useful architecture, providing interesting content, a...

http://usamadar.com/2012/07/14/all-you-need-to-know-about-search-engine-optimization/

If you work with Web Development or Javascript / Ajax a lot you must have come across browser’s same origin policy or SOP. Same Origin Policy or SOP is a security concept in which documents ret...

http://usamadar.com/2012/06/24/getting-around-browsers-same-origin-policy-sop-with-proxies-script-injection-jsonp-and-cors/

I recently had to implement my own version of RFC 2617 which addresses the digest authentication in http protocol. This RFC is an improvement over RFC 2069 which was the previous version of Di...

http://usamadar.com/2012/06/11/implementing-http-digest-authentication-in-java/

Do you know why your developers get so irritated when someone (You) distract them? After all you have a software in production, and so your developers should be able to constantly adjust to the c...

http://usamadar.com/2012/06/04/the-makers-schedule-know-how-your-developers-function/

Why is Software so hard to build? I don't necessarily feel the same way. Software part creativity and part repetition.  Some part of it can be automated while the other part of it can not ...

http://usamadar.com/2012/05/07/why-is-software-so-hard-to-build/

I came across a very interesting phenomenon today. Something i have known and observed for a very long time. I often wondered that in our business (Technology) people who generally rate themselve...

http://usamadar.com/2012/04/22/unskilled-and-unaware-of-it-the-dunning-kruger-effect/

I am beginning to have a liking for the new stuff everyone is buzzing about. The server side V8 based javascript framework called Node.js. In the start when i heard about it at a hacker’s get...

http://usamadar.com/2012/04/19/asynchronous-non-blocking-backends-node-js-is-cool/

I have heard a couple of point of views on this topic. Some think the role of scrum master needs to be consistently with one person and one person only. This is much like the role of a Project Ma...

http://usamadar.com/2012/03/15/should-you-rotate-the-scrum-master-role/

Over the years i have worked and integrated with many payment systems and gateways. Some have been server-to-server and some have been “front-end” systems. Some have been extremely simple to ...

http://usamadar.com/2012/01/24/paypal-integration-primer-quick-way-to-integrate-online-payments-to-your-website/

Do you know the difference? Don’t worry you are not alone.  Many of the developers i have met or seen the code of , don’t know the difference either. GMT is Greenwich Mean Time whereas UTC i...

http://usamadar.com/2012/01/10/utc-or-gmt/

i have recently designed a quiz with an intention to asses the scrum knowledge of the development team members and scrum masters. This can be a good gauge of if you know your scrum-fu in enough d...

http://usamadar.com/2012/01/07/how-much-do-you-know-scrum-theory/

I work for a company which relies heavily on outsourcing to an offshore company in Ukraine. Actually last 3 companies i worked for, relied heavily on outsourcing in india, pakistan , china etc. I...

http://usamadar.com/2012/01/05/how-to-make-offshore-software-outsourcing-work-for-you/

i had a relatively hard time to put a “follow me on twitter” badge (with a Hyperlink) to my email signature in Apple mail. So i thought i would share this with other people. The process is fa...

http://usamadar.com/2012/01/03/putting-a-follow-me-on-twitter-badge-to-your-apple-mail-signature/

We had a decision to make about which version control system to switch to. We were using CVS and were not happy with it. So we decided to do a quick analysis of what options do we have. We curren...

http://usamadar.com/2010/05/21/comparitive-analysis-of-available-version-control-systems/

Server bandwidth is the single most important factor in the performance of your web site. The math to determine what bandwidth you need is, in essence, very simple: hits/second * average size of ...

http://usamadar.com/2010/05/21/how-much-bandwidth-do-you-need/

O -notation is the most common notation used to express an algorithm’s performance in a formal manner. Formally, O -notation expresses the upper bound of a function within a constant factor. Sp...

http://usamadar.com/2010/05/18/o-notations/

Java or C++ , there really is no simple answer, rather it is about right tool for the right job

http://usamadar.com/2010/05/18/java-or-c/