A composite index can only be used efficiently if the query matches the leftmost columns of the index. For example, if you have a composite index on (name, city), it can be used for queries that ...

Learn how to use indexes to improve the performance of your database queries. Find out how to create, choose, and maintain indexes, and how to test and measure their impact.

an IN subquery where the column in the inner subquery is indexed correlated subqueries, where the column being compared with the correlated reference is indexed join-queries ... indexes for all ...

The query optimizer has to figure out by itself what indexes to use to avoid brute ... I’ll explain this by using examples in DDL, using SQL Server syntax. The short version of this is fairly ...

A few months ago a new option was added to the Sql.Database and Sql.Databases functions in Power Query in Power BI and Excel which allows Power Query queries that combine data from different SQL ...

On the basis of building theoretical frame of keywords search queries and online shopping transaction volume, this paper took Taobao.com - the largest E-commerce retail website in China-as an example, ...

Abstract: This paper describes AIM (Automatic Index Manager), a configurable index management system, which identifies impactful secondary indexes for SQL databases ... recommending wide composite ...