if the physical ram is 2GB, and I would like to allocate 1GB for
firebird database cache. Assume that page size for database is
8192byte.

The buffer that I can create for database cache is 1GB/8192 = 128000
page ?

if the above calculation is correct, I am getting a problem to
allocate 128000 page of cache for my database.

gfix -B 128000 abc.gdb

I am getting error:
"bad parameters on attach or create database"

Please help.