Subject Re: Firebird memory requirements per user
Author russellbelding
Thanks Helen, your reply is half the answer I want. You book will not
be a doorstopper in my office. It will be in easy reach of my hands.


--- In, Helen Borrie <helebor@t...>
> At 02:02 AM 23/07/2004 +0000, you wrote:
> >Are there any published studies on the memory required by a
> >server per connected client? If so where?
> >
> >A potential client for my FB application is asking me this question
> >and I cannot answer it. I can look at the memory use by the
> >service on my Win2K workstation when several users are connected to
> >the database but using the Win2K task manager for this gives
> >(to me) results.
> Estimating (from Chapter 1 of the forthcoming doorstopper):
> Server Memory (All Platforms)
> Estimating server memory involves a number of factors:
> • Firebird server process: The Firebird server process makes
efficient use
> of the
> server's resources. The Superserver utilizes around 2MB of memory.
> POSIX, the
> Classic server uses no memory until a client connection is made. On
Windows, a
> small utility service is listening for connection requests.
> • Client connections: Each connection to the Superserver adds
> 115KB, more or less, according to the style and characteristics of
> appli-cations
> and the design of the database schema. Each connection to the
> server uses about 2MB.
> • Database cache: The default is configurable, in database pages.
> Superserver
> shares a single cache (with a default size of 2,048 pages) among
> connections
> and increases cache automatically when required. The Classic server
creates an
> individual cache (with a default of 75 pages) per connection.
> As an estimate, allow 64MB of available RAM for a server and 16MB
for a local
> client. The more clients you add, the more RAM will be used.
Databases with
> large
> page sizes consume resources in larger chunks than do those with
> page sizes.
> Resource usage on the Classic server grows by a fixed amount per
> attachment; on Superserver, resources are shared and will grow
> as needed. Firebird 1.5 will use extra available RAM for sorting if
it is
> available. Memory usage is discussed in more detail in Chapter 6.
> hth
> /heLen