Non Clustered Index | SQL Server Performance Forums

SQL Server Performance Forum – Threads Archive

Non Clustered Index

Hi , I am a bit confuse about the non-clusted index. If I created a covered non-clustered index on columns A,B and C and I perform a query as show below , Select A,B and C From Table1. Means the query will look on the phycal data pages on the non-clustered index without searching the original table ? Thanks
Most likely yes. You can verify this by examining the execution plan (Ctrl+K) in Query Analyzer. Move the mouse over the pictures you see there. On one (I guess the rightmost one), examine the "Argument" section. The object mentioned there should show the name of your covered index. —
Frank Kalis
Moderator
Microsoft SQL Server MVP
Webmaster:http://www.insidesql.de
This is what cover index good for, only traverse index pages to get the targeted data. In order to let query optimizer use the cover index, please make sure the left-most column is selective enough.
Check this link for more info on covering index
http://www.sql-server-performance.com/covering_indexes.asp ——————
Bug explorer/finder/seeker/locator
——————
Travis
Is this connected to SQL server 2005 versioN> Satya SKJ
Microsoft SQL Server MVP
Contributing Editor & Forums Moderator
http://www.SQL-Server-Performance.Com
This posting is provided AS IS with no rights for the sake of knowledge sharing.
]]>