Thread: pgsql: Error out when Gather Merge input is not sorted
Error out when Gather Merge input is not sorted To build Gather Merge path, the input needs to be sufficiently sorted. Ensuring this is the responsibility of the code constructing the paths, but create_gather_merge_plan tried to handle unsorted paths by adding an explicit Sort. In light of the recent issues related to Incremental Sort, this is rather fragile. Some of the expressions may be volatile or parallel unsafe, in which case we can't add the Sort here. We could do more checks and add the Sort in at least some cases, but it seems cleaner to just error out and make it clear this is a bug in code constructing those paths. Author: James Coleman Reviewed-by: Tomas Vondra Discussion: https://postgr.es/m/CAAaqYe8cK3g5CfLC4w7bs%3DhC0mSksZC%3DH5M8LSchj5e5OxpTAg%40mail.gmail.com Discussion: https://postgr.es/m/CAJGNTeNaxpXgBVcRhJX%2B2vSbq%2BF2kJqGBcvompmpvXb7pq%2BoFA%40mail.gmail.com Branch ------ master Details ------- https://git.postgresql.org/pg/commitdiff/6bc27698324a3eadb8a4a5a79d96e16687be6141 Modified Files -------------- src/backend/optimizer/plan/createplan.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-)