Re: Merge David and Goliath tables efficiently

> IMHO the thing that breaks it is the ORDER BY in the merge, which
> likely
> acts as an optimization fence and prevents all sorts of smart things
> including the partitionwise join. I'd bet that if Nicolas replaces
>
>   MERGE INTO "goliath" ca
>   USING (SELECT * FROM "david" ORDER BY "list_id") AS t
>   .

Sorry if it was not clear, however there is no order by in the 2.1
strategy. Then this cannot be the reason of not triggering the optim.

For information I do enable partition join feature with jdbc call just
before the merge:
set enable_partitionwise_join=true