Обсуждение: Union All View execution
Hi,
If we have two queries, Query A and Query B that both return same columns.
If we do Union All View will postgresql execute Query A and then Query B sequentially?
Does the work being discussed around parallel query have the potential to parallely execute both parts of a Union All View?
Also is there a pointer to the latest summary of goals and design for parallel query work?
Thanks!
Cheers,
Ivan
On Thu, Oct 15, 2015 at 11:33 AM, Ivan Novick <inovick@pivotal.io> wrote:
Hi,If we have two queries, Query A and Query B that both return same columns.If we do Union All View will postgresql execute Query A and then Query B sequentially?Does the work being discussed around parallel query have the potential to parallely execute both parts of a Union All View?
The work being currently done will not cover this case. However,
each individual Query's involved in union could be run in parallel, if
they meet criterial for parallel query (like doesn't use parallel-unsafe
clauses).