Search Results for: search optimization

The Optimization That (Often) Isn’t: Index Merge Intersection

Prior to version 5.0, MySQL could only use one index per table in a given query without any exceptions; folks that didn’t understand this limitation would often have tables with lots of single-column indexes on columns which commonly appeared in their WHERE clauses, and they’d wonder why the EXPLAIN plan for a given SELECT would […]

Understanding Performance Optimization Terminology

There are few terms you need to have a good understanding if you’re working with high volume systems. I commonly see these mixed and people not understanding the difference between them. Performance – The performance comes down to performing up to users expectations (or expectations of your boss) which drills down to two important metrics […]

Using GROUP BY WITH ROLLUP for Reporting Performance Optimization

Quite typical query for reporting applications is to find top X values. If you analyze Web Site logs you would look at most popular web pages or search engine keywords which bring you most of the traffic. If you’re looking at ecommerce reporting you may be interested in best selling product or top sales people. […]