Fix eager aggregation grouping on cross-type join keys When a Var of the relation to be partially aggregated is known equal to a GROUP BY expression through an EC, get_expression_sortgroupref() let it reuse that expression's SortGroupClause. If the two are of different types, as with an int2 grouping key joined to an int4 column, the Var was then grouped using the other type's equality operator, which could put unequal values into the same group and give wrong results.
To fix, accept only EC members of the same type as the grouping expression. A cross-type Var is then treated like any other join key and gets a SortGroupClause built for its own type. Reported-by: Robert Haas <[email protected]> Author: Richard Guo <[email protected]> Discussion: https://postgr.es/m/ca+tgmob7ism9ykrm44vjuduacchw-fy54mv5njptztl9uny...@mail.gmail.com Backpatch-through: 19 Branch ------ master Details ------- https://git.postgresql.org/pg/commitdiff/d764d61af3160f725ac087ccc05d9ccf03af8312 Modified Files -------------- src/backend/optimizer/util/relnode.c | 4 +++ src/test/regress/expected/eager_aggregate.out | 44 +++++++++++++++++++++++++++ src/test/regress/sql/eager_aggregate.sql | 23 ++++++++++++++ 3 files changed, 71 insertions(+)
