David Osborne <david(at)qcode(dot)co(dot)uk> writes:
> Hi, I was wondering if someone could help us work out why this query is so
> slow.
> We've just dumped a database (Postgresql 9.1) and restored it to a new
> instance (AWS RDS 9.6) (via pg_dump, restored to psql)
The first question people will ask is did you re-ANALYZE the new
database? pg_dump doesn't take care of that for you, and auto-analyze
might not think it needs to process the smaller tables.
regards, tom lane