Column Order Matters For Indexes

Bert Wagner violates Betteridge’s Law of Headlines:

When beginning to learn SQL, at some point you learn that indexes can be created to help improve the performance of queries.

Creating your first few indexes can be intimidating though, particularly when trying to understand what order to put your key columns in.

Today we’ll look at how row store indexes work to understand whether index column order matters.

Despite the flagrant violation, you should check out Bert’s post, as it’s a good one.

Related Posts

Adaptive Joins and Index Width

Erik Darling wants to pump your indexes up: Now, there’s an Extended Event that… Used to work. These days it just stares blankly at me. But since I’ve worked with this before, I know the problem. It’s that Key Lookup — I’ll explain more in a minute. Adaptive joins won’t do all the work for you, […]

Read More

Making Non-SARGable Queries SARGable with an Index

Denis Gobo violates Betteridge’s Law of Headlines: This question came up the other day from a co-worker, he said he couldn’t change a query but was there a way of making the same query produce a better plan by doing something else perhaps (magic?) He said his query had a WHERE clause that looked like […]

Read More

Categories

September 2018
MTWTFSS
« Aug Oct »
 12
3456789
10111213141516
17181920212223
24252627282930