Re: failing to use index on UNION of matviews (Re: postgresql 10.1wrong plan in when using partitions bug) - Mailing list pgsql-performance

On Sun, Feb 04, 2018 at 11:04:56AM -0500, Rick Otten wrote:
> On Sun, Feb 4, 2018 at 10:35 AM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> 
> > Rick Otten <rottenwindfish@gmail.com> writes:
> > > I'm wrestling with a very similar problem too - except instead of
> > official
> > > partitions I have a views on top of a bunch (50+) of unioned materialized
> > > views, each "partition" with 10M - 100M rows.  On 9.6.6 the queries would
> > > use the indexes on each materialized view.  On 10.1, every materialized
> > > view is sequence scanned.

I think it'd be useful to see the plan from explain analyze, on both the
"parent" view and a child, with and without SET enable_seqscan=off,

Justin