Index Design When Handling Sorts

Erik Darling walks us through some of the nuance of index deisgn:

When tuning queries that need to sort large amounts of data, sometimes it makes sense to stick the ordering elements as the leading key column(s) in your index. This allows SQL Server to easily sort your data by that column, and then access other key and included columns to satisfy other parts of the query, whether they’re joins, predicates, or selected columns.

That doesn’t mean that indexes with the sorting element first is always the best idea. Depending on how your query looks, you can sometimes put sorting elements at the end of an index definition and still have your sort be supported.

Read on for an example.

Related Posts

Using Filtered Indexes

Monica Rathbun fills us in on filtered indexes: What is a filtered index?Simply it’s an index with a where clause. It is an optimized non clustered index that can be narrowed down in scope to better fit a subset of data. Example being date ranges, years, non NULLs or specific product types. I wish filtered […]

Read More

Foreign Key Checks and Index Usage Stats

Marek Masko walks through an attendee question: Last week I was speaking at SQLDay 2019 conference in Wroclaw, Poland. My session was about things you should focus on during work with Legacy Databases. One of the topics I discussed was concerning the database usage statistics collection and aggregation (mainly indexes and stored procedures). After the session, one of […]

Read More

Categories

April 2018
MTWTFSS
« Mar May »
 1
2345678
9101112131415
16171819202122
23242526272829
30