thanks MichaelJasson and Ps for ur reply...

I am doing query tuning as part of my work... for that im learning sql architecture and query processor behaviour..

I know page size is...

ur question is not enogh to give u a solution.

1. first decide datatype of new column. r u gng to store only a number or char (fixed or variable lenght)...

best practices are

* frequently used tables must have a clustered index

* no need create index on tables having little records or columns having duplicates (like country, gender etc).

* avoid...

Hi,

this could be because of some unknown blocking issue. Some Indexes could reduce disk queue length considerably. I suggest u to take a trace for 10 mins and analyse queries...