Re: Partitioned tables and relfilenode

On 2017/03/06 17:22, Michael Paquier wrote:
> On Mon, Mar 6, 2017 at 4:18 PM, Amit Langote
> <Langote_Amit_f8(at)lab(dot)ntt(dot)co(dot)jp> wrote:
>> About autovacuum_* parameters - we currently don't handle partitioned
>> tables in autovacuum.c, because no statistics are reported for them. That
>> is, relation_needs_vacanalyze() will never return true for dovacuum,
>> doanalyze and wraparound if it is passed a RELKIND_PARTITIONED_TABLE
>> relation. That's something to be fixed separately though. When we add
>> autovacuum support for partitioned tables, we may want to add a new set of
>> reloptions (new because partitioned tables still won't support all options
>> returned by heap_reloptions()). Am I missing something?
>
> OK. I got confused by the fact that settings on parents should
> super-seed the settings of the children. Or if you want if a value is
> set on the parent by default it would apply to the child if it has no
> value set, which is where autovacuum_enabled makes sense even for
> partitioned tables.

Hmm, setting autovacuum_enabled on partitioned parent should be made to
work after we have fixed autovacuum support for partitioned tables. Using
the parent's value as a default for partitions may not be what we'd want
eventually.

> Leading to the point that parents could have
> reloptions, with a new category of the type RELOPT_KIND_PARTITION.
> Still, it is sensible as well to bypass the parents in autovacuum as
> well, now that I read it. And the handling is more simple.

We will need it though, because lack of automatically updated
"inheritance" (or whole tree) statistics on partitioned tables is a problem.

Thanks,
Amit