I ran a shorter version of David's script with just 6-9 attributes to try to reproduce the problem area (spreadsheet with graph attached). My test is also different in that I compare HEAD with just reverting 40af10b57. This shows a 60% increase in HEAD in runtime for 64MB workmem and 64 byte tuples. It also shows a 20% regression for 32MB workmem and 64 byte tuples.
I don't have anything to add to the discussion about whether something needs to be done here for PG15. If anything, changing work_mem is an easy to understand (although sometimes not practical) workaround. -- John Naylor EDB: http://www.enterprisedb.com
Sort benchmark PG15 vs revert gen ctx JCN.ods
Description: application/vnd.oasis.opendocument.spreadsheet
