Systables in local cache (was: Correcting Next Extent problems).

In <1993Feb23.160915.5802@informix.com> davek@somerset.informix.com (Dave Kosenko) writes: >While Jonathan is correct, I will venture to say that this entire >discussion is misguided. Contrary to what the manuals lead you to >believe, having more than 8 extents will not have any significant >impact on the performance of your system. The reason 8 is used is that >8 extents are tracked in the tblspace shared memory structure. When >there are >8, the tblspace tblspace page for the table will be checked. >For frequently accessed tables, this will cause the TT page to sit in >cache, so there is no great loss. For system tables, it is even less >of a problem, because they are read into *local* cache when sqlturbo >is started up, so accessing that data is really not an issue. >So I wouldn't bother trying to change those extent sizes. Are you saying that each sqlturbo process keeps a copy of the system catalogs in it's stack segment, and therefore size of data dictionary affects process size and memory usage per user???? If this is true, how should one attempt to calculate the effect on memory per user?