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Should MySQL Extend GROUP BY Syntax ?

 | August 17, 2007 |  Posted In: Insight for Developers

Jan has a good article about finding the row matching some value in the group: This is one illustration of group by limitations in SQL language which is not offset by any MySQL specific extensions,yet As you can see if you want to get one row from the group which is sorted some way you […]

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Query_cache and column level privileges

 | August 6, 2007 |  Posted In: Insight for Developers

Recently we were puzzled by question how query_cache works with column level privileges. The question was appeared as we discovered function query_cache_send_result_to_client is called before real parsing of query, so at the moment of execution the query_cache is not able to know which columns are accessed. Looking into source code I found out that in […]

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Sphinx: Going Beyond full text search

 | July 23, 2007 |  Posted In: Insight for Developers

I’ve already wrote a few times about various projects using Sphinx with MySQL for scalable Full Text Search applications. For example on BoardReader we’re using this combination to build search against over 1 billion of forum posts totaling over 1.5TB of data handling hundreds of thousands of search queries per day. The count of forum […]

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PHP Large result sets and summary tables.

 | July 6, 2007 |  Posted In: Insight for Developers

We’re working with web site preparing for massive growth. To make sure it handles large data sets as part of the process we work on generation test database of significant size as testing your application on table with 1000 rows may well give you very dangerous false sense of security. One of the process web […]

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Working with large data sets in MySQL

 | July 5, 2007 |  Posted In: Insight for Developers

What does working with large data sets in mySQL teach you ? Of course you have to learn a lot about query optimization, art of building summary tables and tricks of executing queries exactly as you want. I already wrote about development and configuration side of the problem so I will not go to details […]

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Implementing efficient counters with MySQL

 | July 1, 2007 |  Posted In: Insight for Developers

On many web sites you would see a counter how many time given object – blog post, forum thread, image, movie etc was viewed. This is sometimes handy feature but it can be rather expensive from performance point of view. The nasty thing with counters as they are implemented the most trivial way – they […]

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