• What you need to do is find out WHY things appear to be sluggish at times. Is it due to blocking or is it due to IO stalls or some other form of wait? Each of those possibilities should be analyzed while the activities are in progress. If for some reason (such as complexity of the query leading to bad estimation, improper indexing) table locks (or perhaps even page locks) are being acquired then you could indeed be seeing blocking and if so row lock hints could be a help. If the queries that insert/delete are suboptimal then whatever locks are taken are being held too long and tuning could be the magic bullet you seek.

    LOTS of possibilities here. I recommend getting a tuning consultant in for a few hours remote work. Should be all it takes, and you can learn from how they do their work as well so you can better fix your own problems in the future.

    Best,
    Kevin G. Boles
    SQL Server Consultant
    SQL MVP 2007-2012
    TheSQLGuru on googles mail service