Subject Re: [Firebird-Architect] Inexact database operations
Author Ann W. Harrison
Rick Debay wrote:
> The server. The point was that there are solutions to either calculate
> the results in parallel, or cache them.

The optimizer gets an approximate record count for calculating inexact
costs by counting the number of pointer pages (from RDB$PAGES)
multiplying it by the number of data pages per pointer page (fixed for
each page size) multiplying the result by (the size of a page / byte
length of records). It's imprecise, but "good enough".