good guess for final record number in SELECT?

Short question:
Is there some way to estimate the the row count for some SELECT statement already prepared and bound to a cursor without actually fetching all the rows?

Oracle 9i, Linux, language Python

Here is our problem:

Given one possibly huge SELECT statement which is bound to a cursor. We did not fetch any row yet.

A GUI Tool wants to present a good guess of the final row count to the end user.

So, someone suggested to count the number of rows a certain huge SELECT will return by using 'SELECT COUNT(*) FROM (original-query)' before the 'original-query' is done and use that as the final correct row count.

I guess the server will have to do 'original-query' twice and the count()ed row count will be just a guess, because of concurrent INSERT and DELETE operations. (we are working in READ COMMITTED)

So, is there something significantly faster than COUNT()? Something like 'select ESTIMATE_COUNT(*) from (original-query)'?

Thank you,

Volker

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Volker Apelt