Re: SET EXPLAIN - why are INSERT costs high???

In article <34edb916.0@news.snip.net>, David K. Killough <killougd@ix.netcom.com> writes > >We are stress testing our application and have been pouring over the SET >EXPLAIN OUTPUT to optimize things. Everything looks good but the INSERTs >are still reporting high costs. My theory is that it is handling the INSERT >like a SELECT without a WHERE clause. Our hardware vendor has said that we The costs for insert are complete crap. They are meaningless. >need to reduce these costs before they will tune our database. I don't >think it is possible. I don't think the high costs represent a failure to >optimize. I am very sure about this. Does anybody know the scoop. If so, Agreed. The costs also expect a cpu to disk performance ratio of 100 to 1 which will almost never bo correct.. Ignore them and just look at selects/updates/deletes and may sure they use indexes. >is there any reference in the Informix documentation that I can go to. It >seems like indexes should have some impact on the efficiency of doing >inserts. Does SET EXPLAIN help cost this at all????? Not really. Indexes do slow things down slightly but without indexes your selects will take forever... >thanks, dave k > > -- David Williams Maintainer of the Informix FAQ Primary site (Beta Version) http://www.smooth1.demon.co.uk Official site http://www.iiug.org/techinfo/faq/faq_top.html I see you standin', Standin' on your own, It's such a lonely place for you, For you to be If you need a shoulder, Or if you need a friend, I'll be here standing, Until the bitter end... So don't chastise me Or think I, I mean you harm... All I ever wanted Was for you To know that I care