Programmer's Notes

Preface

In November 2008 I’ve got a nice project, that resulted in a complex search engine, that specializes in clothing. I can’t give the link now, but will do when site officially launches. Key features of such service are:

• Large number of users, which search with various parameters, rate items, leave comments, create articles etc.
• Large database, that is updated frequently

Sure, the site is running on a dedicated server, sure I use caching, but optimal DB is a key to success.

Continue reading ‘Building high-loaded portal – InnoDB vs MyISAM’ »

Preface

This is an introductory post to the series, where I’ll cover all design patterns, their usage, diagrams. Besides patterns, I am going to guide you through the principles of the high-quality application design. We’ll start from these principles (GRASP), and then advance to patterns, see how they use these principles and develop several systems (architecture only). The whole series will take 10-15 posts. However, I don’t have exact plan yet So, let’s go!

So what we’re talking about?

Actually, design pattern is no more, than a proven solution to some common problem. When saying “problem” I mean things you face with when developing the application architecture. These solutions are intended to make you application better – more extensible, flexible, simple.

Common examples of design problems (Let’s agree that in this series “design” means application, not graphics or DB design) are:
Continue reading ‘Creator and Information Expert principles – GRASP (Design patterns series)’ »

Once I had a task to import a number of data from datafeeds (that are in CSV or XML) into MySQL database. See solution in my another post. Here I want to tell about handling large files.

Datafeeds there are 50-200M each, so reading all file at once was not possible due to memory limitations. So we need to split it into portions. Here is the class, that solves the problem of downloading remote file, saving it locally and then reading by portions. Continue reading ‘Working with large files eficiently’ »