Thread: pgsql: Disallow partitionwise join when collations don't match
Disallow partitionwise join when collations don't match If the collation of any join key column doesn’t match the collation of the corresponding partition key, partitionwise joins can yield incorrect results. For example, rows that would match under the join key collation might be located in different partitions due to the partitioning collation. In such cases, a partitionwise join would yield different results from a non-partitionwise join, so disallow it in such cases. Reported-by: Tender Wang <tndrwang@gmail.com> Author: Jian He <jian.universality@gmail.com> Reviewed-by: Tender Wang <tndrwang@gmail.com> Reviewed-by: Junwang Zhao <zhjwpku@gmail.com> Discussion: https://postgr.es/m/CAHewXNno_HKiQ6PqyLYfuqDtwp7KKHZiH1J7Pqyz0nr+PS2Dwg@mail.gmail.com Backpatch-through: 12 Branch ------ REL_12_STABLE Details ------- https://git.postgresql.org/pg/commitdiff/9c4757491683a10f0531bd206850d15dad8cadeb Modified Files -------------- src/backend/optimizer/path/joinrels.c | 4 + src/test/regress/expected/collate.icu.utf8.out | 118 +++++++++++++++++++++++++ src/test/regress/sql/collate.icu.utf8.sql | 22 +++++ 3 files changed, 144 insertions(+)