Re: clarification of parallel query on informix and oracle

David E. Grove wrote: >>Light scans do avoid the >>buffer cache and are used for queries that include a long sequential scan > > of > >>a table and are only used for pages from that table. > > > > I've wondered about that, too. So, if a light scan is to be used, IDS > ignores any pages already in the buffer cache? Suppose the whole table is > already cached (say it was made resident)-- would that affect the answer? > > Thank you. > > DG > > If I recall correctly, one requisite of light scans is that the table must be bigger that the buffer cache.... But you can check this in the manual. It it's such, that the table can't be in memory. And by the way, resident tables by user command will be gone, because the new cache system does this by default. Regards, Fernando Nunes