Support PlaceHolderVars in MERGE actions.
preprocess_targetlist thought PHVs couldn't appear here.
It was mistaken, as per report from Önder Kalacı.
Surveying other pull_var_clause calls, I noted no similar errors,
but I did notice that qual_is_pushdown_safe's assertion about
!contain_window_function was pointless, because the following
pull_var_clause call would complain about them anyway. In HEAD
only, remove the redundant Assert and improve the commentary.
Discussion: https://postgr.es/m/CACawEhUuum-gC_2S3sXLTcsk7bUSPSHOD+g1ZpfKaDK-KKPPWA@mail.gmail.com
Branch
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REL_15_STABLE
Details
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https://git.postgresql.org/pg/commitdiff/3908d6ae115801cc61486b286ab71d91c2cdbb99
Modified Files
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src/backend/optimizer/prep/preptlist.c | 12 +++++-------
src/test/regress/expected/merge.out | 21 +++++++++++++++++++++
src/test/regress/sql/merge.sql | 10 ++++++++++
3 files changed, 36 insertions(+), 7 deletions(-)