Stored Procedure failing on a specific user

Question

I have a Stored Procedure that is constantly failing with the error message \"Timeout expired,\" on a specific user.

All other users are able to invoke the sp just f

Answer 1

Some thoughts...

Reading the comments suggests that parameter sniffing is causing the issue.

• For the other users, the cached plan is good enough for the parameter that they send
• For this user, the cached plan is probably wrong

This could happen if this user has far more rows than other users, or has rows in another table (so a different table/index seek/scan would be better)

To test for parameter sniffing:

• use RECOMPILE (temporarily) on the call or in the def. This could be slow for complex query
• Rebuild the indexes (or just statistics) after the timeout and try again. This invalidates all cached plans

To fix: Mask the parameter

DECLARE @MaskedParam varchar(10)
SELECT @MaskedParam = @SignaureParam

SELECT...WHERE column = @MaskedParam

Just google "Parameter sniffing" and "Parameter masking"