> On Jul 8, 2015, at 8:14 AM, Svein Erling Tysvær svein.erling.tysvaer@... [firebird-support] <firebird-support@yahoogroups.com> wrote:
>
> Take a look here: http://www.firebirdfaq.org/faq361/
>
> I'd add that restore also has a -use_all_space option. If you don't specify this, then pages are filled to approximately 80% (80% is preferable over 100% unless it is a read-only database). See http://www.firebirdsql.org/manual/gbak-cmdline.html or http://www.firebirdsql.org/manual/gfix-pagespace.html for more information.
>

Just being pedantic here. The space reserved depends on the size of the record - the full declared size plus the record header (approx 14 bytes). Firebird computes the number of records that could fit on the page and reserves 16 bytes per record. So if your records are big, you'll reserve less space. A record that consists of a single integer could reserve nearly half the page.

Best regards,

Ann