At 9:35 AM +0000 1/24/07, Barbat, Nicolae : Barclays Wealth Technology wrote:
>Hi All,
>
>We are (still) running Ingres 2.5/0011 patch 7652 on HP-UX 11. Noticed some
>time ago that the cache parameters are the default ones:
>
> .dmf_cache_size .1688************
> .dmf_free_limit .53**************
> .dmf_group_count .102*************
> .dmf_memory .5128192*********
>
>on a system with around 350 users. I was thinking to increase the value for
>group_count to 384.
>Is anybody aware of any problems with 2.5 handling larger cache values? And
>should I expect any real benefit by doing this?

I don't know of any 2.5 issues with larger caches, and in any case what
you propose hardly counts as "large". You might want to ease up
the dmf_cache_size to 5000 or 10000 while you're at it.

2.0 had some issues with performance with very large caches (many 10,000's
of pages), but the major performance problems were fixed for 2.5.
They were related to scanning the cache for a specific table's pages,
and 2.5 and later have a table-page crossref to facilitate that.

Karl