Re: Upgrade recommendations

> Dirk Moolman asked (as part of a continuing conversation): >> How big is this database / databases (instance) ? William Weaver wrote: > Almost 18GB in its current form. > > By the way, that leads me to another related question. I've never done an > SE to IDS conversion before. In terms of sizing of tables/indexes for > extents in IDS, are the .dat and .idx files of SE comparable in terms of > their space requirements? In other words, can I calculate the extent size > based directly on the size of these files or do I need to add/subtract some > amount of fudge factor? It depends on how fancy you want to get, but to a first order approximation, the sizes will be the same. The data section will be slightly larger under IDS because of the internal fragmentation of pages and because of the page overhead (28 + 4 * N) bytes per page for N rows in a page. The index section will be slightly larger too because SE applies leading and trailing compression to character keys, and because IDS uses more bytes to identify where each row is (4 in SE, 5 or 9 in IDS). It also depends on whether you delete rows from your SE tables, and if so, how much spare space is allocated, and what fill factor you use when you create your IDS indexes, and so on. -- Jonathan Leffler #include <disclaimer.h> Email: jleffler@earthlink.net, jleffler@us.ibm.com Guardian of DBD::Informix v2005.02 -- http://dbi.perl.org/