Strip removed-relation references from PHVs in join clauses Commit 9a60f295b stripped the stale PlaceHolderVars left behind by left-join removal from the surviving rels' baserestrictinfo and from EquivalenceClass member expressions, but it overlooked join clauses. A PlaceHolderVar embedded in a join clause can likewise retain the removed rel and join in its phrels, since remove_rel_from_query() fixes up the RestrictInfo's own relid sets but not the PHVs inside its expression.
As before, this is normally harmless, because later processing consults those relid sets rather than the embedded PHVs. However, a restriction clause derived from such an OR join clause inherits the stale PlaceHolderVar, and when the derived clause is translated for an appendrel child, pull_varnos() recomputes its relids and folds the removed relation back in. The rebuilt clause then references a no-longer-existent relation, tripping an assertion during path generation. Fix by also stripping the removed relation from the PlaceHolderVars in the surviving rels' join clauses, including the sub-clauses of any OR clause. Like 9a60f295b, this is only reachable on v18 and later, where match_index_to_operand() began ignoring PlaceHolderVars. Author: Arne Roland <[email protected]> Reviewed-by: Tender Wang <[email protected]> Reviewed-by: Richard Guo <[email protected]> Discussion: https://postgr.es/m/[email protected] Backpatch-through: 18 Branch ------ master Details ------- https://git.postgresql.org/pg/commitdiff/d68576bcfc7227d94c4391a3c34aadb8dbf8a3c7 Modified Files -------------- src/backend/optimizer/plan/analyzejoins.c | 78 +++++++++++++++++++++++++++++-- src/test/regress/expected/join.out | 12 +++++ src/test/regress/sql/join.sql | 7 +++ 3 files changed, 92 insertions(+), 5 deletions(-)
