Re: Slow planning, fast execution for particular 3-table query

On Mon, Nov 04, 2019 at 03:04:45AM +0000, David Wheeler wrote:
> Postgres version 9.5.19
> Each of the tables has between 3-4 indexes, and all the indexes include tid as first parameter.

On Mon, Nov 04, 2019 at 12:00:59AM -0500, Tom Lane wrote:
> If this *is* the cause, v11 and up have a performance improvement that
> you need:

But note that index definition will be prohibited since:

https://www.postgresql.org/docs/9.6/release-9-6.html
|Disallow creation of indexes on system columns, except for OID columns (David Rowley)
|Such indexes were never considered supported, and would very possibly misbehave since the system might change the
system-columnfields of a tuple without updating indexes. However, previously there were no error checks to prevent them
frombeing created.
 

Justin