Subject Re: [firebird-support] Re: Issue with Database Cache Size on FB 3.0
> ---In, <fabianch@...> wrote :
> Something funny is going on regarding the memory consumption, I have attached screenshots showing the memory counters.
> If you look at the process itself (file TaskManager_Process_Firebird_Only_Consumed_2GB.jpg), it only consumed 2 GB.
> If you look at Windows Task Manager (file TaskManager_Performance_ALL_RAM_Consumed.jpg), where it says "Physical Memory,
> just under the memory graph where it shows 3.13 GB used, the cached memory is 29963 Mb. I know Firebird is who consumed that
> CACHED memory because I am forcing the DB to read 70GB on purpouse, but why is the memory not showing under the process
> Firebird ? (it only shows 2GB used there).

  File system cache maintained by OS, not by Firebird (or any other app). It is shared between all processes and it is impossible to
assign any part of it to the some process.

My aim is to set the config to only use RAM (no file system cache), and to place the hole DB in RAM for caching when reading,

  Use RamMap utility (by SysInternals) to see which files is cached by OS and how much.

> I am struggling to find a config mix that will do that. The config variables are:
FileSystemCacheThreshold = 0
FileSystemCacheSize = 80
TempCacheLimit = 24576M (I am not sure what this value is for, it seems to mean the maximum amount of temporary things to have in memory, like DB read cache)

  No, it is used mainly for sorting and not for the page cache.

The above 3 variables are the ones I am playing with, plus the DefaultDBCachePages = 90000 in Databases.conf

  This is the only setting for cache size. If your db have page size of 8KB it will consume ~703MB of memory, if page size is
16KB, it will take near 1.4 GB.

Hope it helps,