Re: partition tree inspection functions

Hi,

On 2018/10/01 15:03, Michael Paquier wrote:
> On Thu, Aug 09, 2018 at 01:05:56PM +0900, Amit Langote wrote:
>> Attached updated patch.
> 
> So, except if I am missing something, what we have here is a patch which
> has been debatted quite a bit and has semantics which look nice.

Thanks.

>  Any
> objections if we move forward with this patch?

I wasn't able to respond to some of issues that Jesper brought up with the
approach taken by the latest patch whereby there is no separate
pg_partition_level function.  He said that such a function would be useful
to get the information about the individual leaf partitions, but I was no
longer sure of providing such a function separately.

> +-- all tables in the tree
> +select *, pg_relation_size(relid) as size from
> pg_partition_children('ptif_test');
> +    relid    |  parentid  | level | isleaf | size
> +-------------+------------+-------+--------+-------
> + ptif_test   |            |     0 | f      |     0
> + ptif_test0  | ptif_test  |     1 | f      |     0
> + ptif_test1  | ptif_test  |     1 | f      |     0
> + ptif_test2  | ptif_test  |     1 | t      | 16384
> + ptif_test01 | ptif_test0 |     2 | t      | 24576
> 
> One thing is that this test depends on the page size.  There are already
> plan modifications if running the regress tests with a size other than
> 8kB, but I don't think that we should make that worse, so I would
> suggest to replace to use "pg_relation_size(relid) > 0" instead.

Might be a good idea, will do.

> I have moved the patch to next CF for now.

Thank you, I'll submit an updated version soon.

Regards,
Amit