>> > How do we know the individual table sizes in a DB?
>>
>> The gstat tool (-a switch) can tell you how many pages each table
>> takes up as well as the size of the data page.
>
> The same can be done programmatically or via SQL by counting the number
> of page entries in the RDB$Pages table grouping by the Table/Relation
> ID.

Not the same, because one entry in rdb$pages points to one pointer page,
which references up to 955 data pages (for 4k page size)

Ivan
http://www.volny.cz/iprenosil/interbase/