Re: executor relation handling

Amit Langote <Langote_Amit_f8(at)lab(dot)ntt(dot)co(dot)jp> writes:
> 0004: removes useless fields from certain planner nodes whose only purpose
> has been to assist the executor lock relations in proper order

I've pushed most of 0004 now; obviously, not the parts removing
PlannedStmt.rowMarks, since that's not possible without rearrangement
of the executor's RowMark handling.

I didn't like the idea of unifying ModifyTable.nominalRelation with
the partition root info. Those fields serve different masters ---
nominalRelation, at least in its original intent, is only meant for
use of EXPLAIN and might have nothing to do with what happens at
execution. So even though unifying them would work today, we might
regret it down the line. Instead I left that field alone and added
a separate rootRelation field to carry the partition root RT index,
which ends up being the same number of fields anyway since we don't
need a flag for is-the-nominal-relation-a-partition-root.

Still need to think a bit more about whether we want 0005 in
anything like its current form.

regards, tom lane