SQL Select Query Timing Out

Question

I have a table in my SQL Server 2008 database called dbo.app_additional_info which contains approximately 130,000 records. Below shows the structure of the table.

When I run a query like the one below in SQL Server Management Studio 2008

select app_additional_text
from app_additional_info
where application_id = 2665 --Could be any ID here

My query takes a long time to execute (up to 5minutes) and sometimes it times out. This database is also connected to a Web Application and when it runs the above query, I always get a timeout error.

Is there anything I can do to speed up the performance of my query?

Your help with this would be greatly appreciated as this is grinding my web application to a halt.

Thanks.

Update

Below shows my execution plan from SSMS (I apologise for poor quality)

Answer 1

based on the limited info in the question, it looks like you are doing a table scan because there is no index on application_id. So, try this:

CREATE INDEX IX_app_additional_info_application_id on 
                app_additional_info (application_id)

your query should run much faster now.