estimate and warning before executing query

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We currently have an DBMS that estimates the cost of a query. If the = cost is
higher than a certain value the DBMS itself returns an error stating the query is too expensive. Cursing in the church (list) of course, but this ingres. The query is not executed actually. The query optimizer itself creates a plan and checks the cost. When too high it gives the signal. = Is a
lot faster than any solution using something like rownum < value, = especially
with ordered queries. Is there such a threshold in oracle that can be = set
with the same benefits:
- early warning of 'costly' queries
- doing only optimizing for the query
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Looking for handles to start digging.
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TIA,=20
Eric Buddelmeijer=20
DBA=20
e-mail Eric.Buddelmeijer_at_elegant.nl=20
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