Re: Getting number of matched records from query - Mailing list pgsql-hackers

From Stephan Szabo
Subject Re: Getting number of matched records from query
Date
Msg-id 20031101214918.D58021@megazone.bigpanda.com
Whole thread Raw
In response to Getting number of matched records from query  (Michael Owens <mike@mikesclutter.com>)
List pgsql-hackers
On Sat, 1 Nov 2003, Michael Owens wrote:

> Isn't this information (the number of matched records) available to the
> backend --- even in the case of LIMIT? All matched records still have to be
> materialized right? Therefore the record count should be available and could
> therefore be available to the client. Is this correct?

No.  For many plans, the entire record set does not have to be fully
materialized in the presence of LIMIT. In general, the limit node should
have the effect of making such plans more likely to be chosen.


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