pgsql: Fix postgres_fdw to cope with duplicate GROUP BY entries.

2018-01-12 Thread Tom Lane
Fix postgres_fdw to cope with duplicate GROUP BY entries. Commit 7012b132d, which added the ability to push down aggregates and grouping to the remote server, wasn't careful to ensure that the remote server would have the same idea we do about which columns are the grouping columns, in cases where

pgsql: Fix postgres_fdw to cope with duplicate GROUP BY entries.

2018-01-12 Thread Tom Lane
Fix postgres_fdw to cope with duplicate GROUP BY entries. Commit 7012b132d, which added the ability to push down aggregates and grouping to the remote server, wasn't careful to ensure that the remote server would have the same idea we do about which columns are the grouping columns, in cases where