Обсуждение: Obtaining a total number of records in a cursor (Count)

I am curious to know if there is a command to obtain the number of
records (tuples) in a cursor such as a count(*)?  I have an app. using
the libpq API that allows the user to search a database and then stores
those results in a cursor... in turn, the app. allows the user to scroll
through the resutls n at a time.  However, I also want to display the
total number of records returned from the search.  It seems highly
innefficient to do a SELECT count(*) and then standard SELECT of the
same query...  After declaring a cursor and passing resutls into it...
is there a command, temporary table, or session in memory that I can
obtain a total count of records for that cursor?

Regards,
Michael

Michael Dunn <michael@2cactus.com> writes:
> is there a command, temporary table, or session in memory that I can
> obtain a total count of records for that cursor?

Not short of reading out the tuples ... in general there is no way to
predict the number of tuples that a query will return, except by
computing them.

            regards, tom lane