Re: Online Extent Sizing

Russell Pears (russell@excelsis.demon.co.uk) wrote: > I am currently running Informix Online V5.0 and am attempting to estimate the > initial and subsequent extent sizes for a *LARGE* database ( some 500 odd > tables). > Having used the algorithm in the manual I find I am getting somewhat wild > results. For starters the manual doesn't accomodate rows > pagesize. > The database in question was dbexported from SE and imported as is. The > figures I have calculated are sometimes greater, sometmes smaller than those > currently repored using tbcheck -pt. > Can someone throw some light on this ?? > Is there a better method of working these figures out ?? > Ta muchly ... > -- > Russell Pears I know it may sound silly, but the accurate way to estiamte the extent sizes is to create the table, poputalte it at least with 100 rows, and then use tbcheck -pt. There are a lot of cases not covered with the standard formula: large rows, varchars, non unique index and blobs. If your not in one of these cases formula is find. Renato Santis