> It's looks like firebird can't allocate more than 2GB of RAM. When I
> decrease Page Buffers to lower values so my fb memory usage is below

2GB

> every thing look fine bud sometimes I get error that I have not enough
> memory for sort operation but I see that I have at least 1,5 GB free

RAM

> and a lot of disc space.

I would recommend switching to Classic server -- you will get better
response across the databases. Though you will need to reduce the
amount of cache memory per connection (a setting of up to 500 pages is
good).

Maximizing the amount of memory that Firebird uses is not the complete
answer to improving application/database performance -- it is just one
part of the complete/complex answer.


Sean