On 2018-Dec-06, Amit Langote wrote: > The partitionwise join related > changes in PG 11 moved the add_child_rel_equivalences call in > set_append_rel_size such that child EC members would be added even before > checking if the child rel is dummy, but for a reason named in the comment > above the call: > > ... Even if this child is > * deemed dummy, it may fall on nullable side in a child-join, which > * in turn may participate in a MergeAppend, where we will need the > * EquivalenceClass data structures. > > However, I think we can skip adding the dummy child EC members here and > instead make it a responsibility of partitionwise join code in joinrels.c > to add the needed EC members. Attached a patch to show what I mean, which > passes the tests and gives this planning time: Robert, Ashutosh, any comments on this? I'm unfamiliar with the partitionwise join code. -- Álvaro Herrera https://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
