Re: extents

ken, > While we are on the subject of extents ... > > I have seen a lot of talk about setting up extents correctly and > maintaining them, but no one ever really gives specifics. > > So, does anyone have a good method (magic formula) for determining how > big to set the initial extent size and the next extent size for dynamic tables? i'm sure that there are other opinions, but this is mine. the question also depends on what is really a dynamic table? a table could have 1 million rows, and daily drop down to 0 and then back up to a million, but be fairly steady around that million mark. or a table could start out with a small number of rows and grow indiscriminately, with no reasonable growth pattern. i think the basic idea is this: for a dynamic table, figure out roughly what this table is going to do, then look at how much space you can give to this table, with the idea that a some or even a lot of it might be empty space from time to time. the idea is simply to not let your table get fragmented all over the disk, and keep the number of extents down to a minimum. if you end up with a few hundred k or a few meg of unused space to keep the table in one or two extents, that might be worth the space. of course, if you are tight on space that is a problem. it is a balancing act, in which every situation is different. you just have to judge what is the best scenario for your enviornment, between not wasting too much space, and keeping the number of extents down. a bit nebulous, i hope this helps, any other thoughts? mickm