Re: Question on the order of execution of UPDATE STATISTICS

sujata_soman_at_omm-la2-infotech-001@internet.omm.com wrote: > > hi all, > Does it matter what order we run the UPDATE STATISTICS command ? > That is, if > we are running update statistics low on the table, and high on all > columns heading an index, which should precede what ?? Well, the HIGH mode will also run a LOW for you. If you don't want it to, then you must use the DISTRIBUTIONS ONLY syntax. > Does it matter if they are done concurrently ?? No. > Speaking of which, does anybody know if there are any > problems > if the update statistics job for the whole database is split into 7-8 > jobs and > run parallelly? What are the considerations, if any ?? No. That's EXACTLY what you should do for large databases. You can then also vary the frequency of each job. Static tables can be updated once a week, and volatile tables can be updated several times a day, or something. You should also run benchmarks to determine the strategy to use for each table. If a MEDIUM gives the same performance as a HIGH, then you can save time and disk by using the MEDIUM. UPDATE STATISTICS is no longer a command...., it's an ART FORM! ;-) Hope that helps, -- Mark. +----------------------------------------------------------+-----------+ |Mark D. Stock - Informix SA http://www.informix.com |//////// /| |mailto:mdstock@informix.com FAQ http://www.iiug.org |///// / //| | +-----------------------------------+//// / ///| | Tel: +27 11 807 0313 |If it's slow, the users complain. |/// / ////| | Fax: +27 11 807 2594 |If it's fast, the users keep quiet.|// / /////| |Cell: +27 83 250 2325 |Therefore, "No news: travels fast"!|/ ////////| +----------------------+-----------------------------------+-----------+