Re: UNION causes horrible plan on JOIN

On Mon, Oct 28, 2019 at 04:30:24PM -0700, Craig James wrote:
> On Mon, Oct 28, 2019 at 3:45 PM Justin Pryzby <pryzby@telsasoft.com> wrote:
>
> > On Mon, Oct 28, 2019 at 03:40:58PM -0700, Craig James wrote:
> > > On Postgres 9.6 (config below), I have a case I don't understand: three
> > > tables that can be separately queried in milliseconds, but when put
> > > together into one view using UNION, take 150 seconds to query. Here's the
> > > rough idea (actual details below):
> >
> > Do you want UNION ALL ?
> >
> > UNION without ALL distintifies the output.
> > https://www.postgresql.org/docs/current/sql-select.html#SQL-UNION
>
>
> Interesting idea, thanks. But it makes no difference. Tried it and got the
> same bad performance.

Could you mail the list the plan with union ALL ?