Re: Does Postgresql 10 query partitions in parallel?

Maltsev Eduard schrieb am 06.12.2017 um 14:11:
> I'm curious if the new feature of Postgresql allows to take advantage
> of multiple cpus on server, and multiple servers (fdw), for larger
> read only queries (Data mining). In general there should be some
> worker that queries partitions and merges the results, and I expect
> it to be done in parallel. This becomes critical when foreign tables
> are used, I suppose.

Postgres 9.6 started supporting parallel queries and this has been extended in 10

This has not been "integrated" with the new declarative partitioning.
I think Postgres 11 will support parallel execution based on partitions.

However with foreign tables, a lot of work is pushed to the foreign server (e.g. joins, where clause, aggregation) and whatever gets pushed down to the foreign server might be executed in parallel (subject to the restrictions on parallel query on _that_ server).
I don't think requests to multiple foreign servers are executed in parallel though.

Thomas