Re: Extents

"COOPER, Joseph" wrote: > > > I have one table that is 70,000,000 records & we feel will grow to > > 90,000,000 > > It is in it's own dbspace and has additional chunks allocated to it. > > > > I had a problem with it yesterday (Error 136) and had to unload, drop, > > rebuild, & reload. I called Informix and they suggested I > > set the first > > extent at 24 and next extent at 24. I'm not real comfortable > > with that. > > Being as this is the only table in the dbspace, should I make > > the first extent the size of the page? And next extent what? > > Any extent must be a multiple of the page size. So setting the first > extent to the page size would be setting it to the minimum that it > can be. I find it very suspicious that informix would recommend a value > of 24. I am hoping that there is maybe some other > information/circumstances that you have not mentioned. The smallest size is actually 4 pages. :-) With 70,000,000 records I can't see where 24 comes from either. > If it was me I would do > dbaccess $dbname > q -- for query language > i -- info > type in the table name > s -- for status > This should show you the row size for the table. > > To get a rough idea of the size of the whole table compute > > num_rows * row_size > > This will give you a value which you should be able to use for > your first extent size. ( you'll have to work out the value in kb > so that you can use it with the extents clause ) > > I have numerous tables with first extents around the 5120 mark and > my larger tables can have first extents around the 40 Mb mark. I can > also tell you that the databases that I deal with are tiny and it is > not uncommon to hear of first extents around the 2Gb mark. Yes, I have several tables with the first extent size 2 Gb. Cheers, -- Mark. +----------------------------------------------------------+-----------+ | Mark D. Stock mailto:mdstock@mydas.freeserve.co.uk |//////// /| | http://www.informix.com http://www.informixhandbook.com |///// / //| | http://www.iiug.org +-----------------------------------+//// / ///| | |This email will self-destruct in |/// / ////| | |10 sec. If you received this email |// / /////| | |in error, sorry about the mess. |/ ////////| +----------------------+-----------------------------------+-----------+