SQL Server Performance Tuning with SSD drives

Home » Advice for New Developers » SQL and Databases » SQL Server Performance Tuning with SSD drives
Photograph of a SSD Drive Array

Recently when explaining to a student the basics of database design and the need for primary keys, foreign keys and indexes generally, I fired up SQL/Server 2012 and typed in a few simple examples on my laptop.

A very brief summary of this is that you need primary keys to uniquely identify rows in a table, and you use foreign keys to link to primary keys in other tables. Additionally an index must be specified on each foreign key (if you use it as an access method rather than just referential integrity). You can also specify additional indexes unique or otherwise as you see fit, taking into account your access methods (paths) and also being careful not to get too carried away with indexing due to insert performance and space considerations.

So I set up a simple example with a couple of tables, customers and orders. I then used Red Gates SQL Data Generator 2 to generate a million rows in the tables because the first time I tried my laptop was taking less than a millisecond to return the data and the times were coming out as zero.

So to repeat the tests with more data: I then started off with a table scan, tried to access via a unique id (without a primary key defined) and compared the timings, so far so good.

When I tried to access all customers whose names begin with “A”, I got 70,000 returned in a quarter of a second or so. It was doing a table scan. When I added an index to customer name, the times increased by about 25%. The only explanation I have is that because my laptop uses dual Samsung 256GB SSD’s, data access is so quick anyway, using an index results in more IO and hence slower access.

I need to do some more work here to understand whats happening here. Expect future blog posts on this subject.

 

About Phil

I have been working as a software developer since 1983. This blog could have been called "From Fortran 77, C and Cobol to C# in 20 (not so) easy years", but it doesn't sound quite right somehow. Besides I'm talking about what's happened since 2003, not before!

Leave a Reply

Your email address will not be published.


You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code class="" title="" data-url=""> <del datetime=""> <em> <i> <q cite=""> <s> <strike> <strong> <pre class="" title="" data-url=""> <span class="" title="" data-url="">




Top Posts & Pages

Categories

Recent Posts

Recent Comments

Archives

Blogroll

  • Mike Cohn's Blog
  • Scott Hanselman's Blog
- mike@mountaingoatsoftware.com

I wrote 26 blog posts during 2020. In case you missed some of them, here are the most popular.

- mike@mountaingoatsoftware.com

It can be very tempting to schedule a week without any meetings. But there are better ideas.

- mike@mountaingoatsoftware.com

Doors are now open (for a limited time only) to my new course: Estimating with Story Points.

- mike@mountaingoatsoftware.com

In this final video on creating estimates with story points, I help you overcome one of the biggest

- Scott Hanselman

Tailscale is a zero config mesh "VPN" that runs atop other networks and effectively "

- Scott Hanselman

Last year kind sucked, and the end of last year was particularly lame. I got off Twitter for a while

- Scott Hanselman

I think we can all agree 2020 sucked. Hopefully 2021 will be better. I've been a remote worker

- Scott Hanselman

The Stream Deck! (amazon link) is a lovely little device with bright LCD buttons that you can progra

- Scott Hanselman

Can you believe it's been 6 years since my last Tools list? Tools have changed, a lot are onlin

Meta