Still celebrating National IT Professionals Day with 3 months of free Premium Membership. Use Code ITDAY17

x
?
Solved

Creating Indexes on a Table And Improving performance

Posted on 2009-07-13
1
Medium Priority
?
198 Views
Last Modified: 2012-05-07
My table has a composite primary key on five columns, so indexes also have five columns. If I want to improve performance can I drop the composite index and build an index on each of the five columns individually? Would this help me in improving performance?
0
Comment
Question by:ken hanse
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
1 Comment
 
LVL 11

Accepted Solution

by:
anilallewar earned 1000 total points
ID: 24846559
Not necessarily; depends on the data distribution. Is your primary key is clustered? If so ensure that the most frequent column on which you query is the first in the primary composite key. If you use group by column create seconday indexes with first column in primary key and the group by columns. This way you can use the physical ordering clreated by the clusterred index and the group by column.

I had a similar situation for a reporting application which had around 40 million records and close to 400 bytes per row. The table previously had a primary key on identity(sequence) column and indexes on all other columns that could be part of dynamic select statements. The performance was poor.

We changed the index structure to have primary key on the 2 most used columns and the sequence(resulting in unique primary key) and non-clustered indexes on other columns which were part of group by. The non-clustered indexes were created as combination of first column in primary key and group by column.

The performance improvment we got was close to 4000% on an average!!
0

Featured Post

VIDEO: THE CONCERTO CLOUD FOR HEALTHCARE

Modern healthcare requires a modern cloud. View this brief video to understand how the Concerto Cloud for Healthcare can help your organization.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

I'm trying, I really am. But I've seen so many wrong approaches involving date(time) boundaries I despair about my inability to explain it. I've seen quite a few recently that define a non-leap year as 364 days, or 366 days and the list goes on. …
An alternative to the "For XML" way of pivoting and concatenating result sets into strings, and an easy introduction to "common table expressions" (CTEs). Being someone who is always looking for alternatives to "work your data", I came across this …
This tutorial will teach you the special effect of super speed similar to the fictional character Wally West aka "The Flash" After Shake : http://www.videocopilot.net/presets/after_shake/ All lightning effects with instructions : http://www.mediaf…
Sometimes it takes a new vantage point, apart from our everyday security practices, to truly see our Active Directory (AD) vulnerabilities. We get used to implementing the same techniques and checking the same areas for a breach. This pattern can re…

660 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question