CODEWITHSUNDEEP
sql-serversql-server-profiler
Bruce
Bruce

Reputation: 2213

column indexing and sql profiler

I have enabled sql profiler and identified several queries that are taking a long time to execute.

For example: 

Select A from table_A where B = 2

My question is, based on above query, do I create indexes on column A or B? or A and B?

Upvotes: 1

Views: 170

Answers (4)

AnandPhadke
AnandPhadke

Reputation: 13506

Create seperate indexes on B and A. Creating index on A is to avoid KEY LOOKUP.

Upvotes: 0

usr
usr

Reputation: 171178

Index on B including column A. The where can use a seek on B while still returning A.

Upvotes: 0

mchollan
mchollan

Reputation: 1

I would create an index on column B because that is what sql server is doing the comparison on. Afterwards I would run the profiler again to see if adding the index negatively impacts other queries.

Upvotes: 0

themel
themel

Reputation: 8895

Your index should be on B since that's what is in your condition. You might benefit from just trying out all the ways and looking at the resulting execution plans.

Upvotes: 1

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