• arkiboys (5/8/2014)


    hi grant.

    as I send this text I have your book with me.

    infact I carry your book in my bag every day as it is a useful book.

    ok. I will read about what you have suggested.

    but I still do not see why applications which hit tge database is sometimes

    fast but most of tge time slow

    surely indexes are good if the queries are sometimes fast.

    any further suggestions please?

    Thankyou.

    Thanks for the kind words.

    Without seeing a lot more detail on what's running on your systems, wait statistics, structures, queries, blocking, resource use & contention, I couldn't even really hazard an educated guess. Two areas that intermittent performance problems can come from are either bad parameter sniffing, or, out of date statistics (which can frequently lead to bad parameter sniffing). Examine the execution plans when the query is slow and fast to see if it's different. If it is, understand why. Is it due to the statistics, or is it due to the values passed to the query, parameter sniffing.

    "The credit belongs to the man who is actually in the arena, whose face is marred by dust and sweat and blood"
    - Theodore Roosevelt

    Author of:
    SQL Server Execution Plans
    SQL Server Query Performance Tuning