Re: [Firebird-devel] FB 2.1 64bit and memory usage ??

[Dmitry Y. <fir...@ya...>]

Leyne, Sean wrote:
> 
> How was the cache 128K page limit arrived at?

IIRC, it always existed (at least since IB6). Originally it was 64K 
pages and the limit has been increased to 128K pages in v2.0.

> Could the limit be increased to 256K and beyond; for 32Bit?

Yes, it could. The question is who will be responsible for the too large 
values (> 2GB in total). Should we adjust the specified size to some 
hardcoded limit before allocating memory or rely on the OS kernel and 
allocate as much as allowed (and perhaps write to firebird.log that we 
couldn't do better).

> Is there a point at which the performance of new cache logic might
> degrade?
> 
> (If we allowed the cache to be 1M pages; would that result in degraded
> performance?)

It's definitely worth measuring before committing the patch into CVS.


Dmitry