Fix estimates for ModifyTable paths without RETURNING.
In the past, we always estimated that a ModifyTable node would emit the
same number of rows as its subpaths. Without a RETURNING clause, the
correct estimate is zero. Fix, in preparation for a proposed parallel
write patch that is sensitive to that number.
A remaining problem is that for RETURNING queries, the estimated width
is based on subpath output rather than the RETURNING tlist.
Reviewed-by: Greg Nancarrow <gregn4422@gmail.com>
Discussion: https://postgr.es/m/CAJcOf-cXnB5cnMKqWEp2E2z7Mvcd04iLVmV%3DqpFJrR3AcrTS3g%40mail.gmail.com
Branch
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master
Details
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https://git.postgresql.org/pg/commitdiff/f0f13a3a08b2757997410f3a1c38bdc22973c525
Modified Files
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src/backend/optimizer/util/pathnode.c | 13 ++++++++-----
1 file changed, 8 insertions(+), 5 deletions(-)