On 10 June 2018 at 04:48, Tom Lane <t...@sss.pgh.pa.us> wrote: > So, IIUC, the issue is that for partitioning cases Append expects *all* > its children to be partitions of the *same* partitioned table? That > is, you could also break it with > > select * from partitioned_table_a > union all > select * from partitioned_table_b > > ?
Not quite. I think what I sent above is the most simple way to break it. Your case won't because there are no quals to prune with, so run-time pruning is never attempted. > If so, maybe the best solution is to not allow a partitioning appendrel > to be flattened into an appendrel generated in other ways (particularly, > via UNION ALL). I also wonder whether it was a bad idea to treat these > as the same kind of path/plan in the first place. That might be the best idea. I'll look into that now. The only drawback I see is that we'll end up pulling tuples through more Append nodes in cases like you mentioned above. -- David Rowley http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services
