Peter Mogensen wrote:
> I have an application where I would really like to be able to look at en
> SQL query and answer the question:
>
> "Is this query capable of returning more than 1 row?"
> Can I conclude that when plan_rows is 1 then there will never be more
> than 1 row returned by the query?
I would say no.
If the planner estimates one row, that means that it guesses that
it will be one or less.
And a query that can potentially return many rows can certainly
also return only one row or none at all.
Yours,
Laurenz Albe
