Re: Inheriting table AMs for partitioned tables

On 2019/03/05 8:47, Andres Freund wrote:
> Hi,
> 
> In the pluggable storage patch [1], one thing that I'm wondering about
> is how exactly to inherit the storage AM across partitions. I think
> that's potentially worthy of a discussion with a wider audience than I'd
> get in that thread.  It seems also related to the recent discussion in [2]
> 
> Consider (excerpted from the tests):
> 
> CREATE TABLE tableam_parted_heap2 (a text, b int) PARTITION BY list (a) USING heap2;
> 
> SET default_table_access_method = 'heap';
> CREATE TABLE tableam_parted_a_heap2 PARTITION OF tableam_parted_heap2 FOR VALUES IN ('a');
> 
> SET default_table_access_method = 'heap2';
> CREATE TABLE tableam_parted_b_heap2 PARTITION OF tableam_parted_heap2 FOR VALUES IN ('b');
> 
> CREATE TABLE tableam_parted_c_heap2 PARTITION OF tableam_parted_heap2 FOR VALUES IN ('c') USING heap;
> CREATE TABLE tableam_parted_d_heap2 PARTITION OF tableam_parted_heap2 FOR VALUES IN ('d') USING heap2;
> 
> It seems pretty clear that tableam_parted_heap2, tableam_parted_d_heap2
> would be stored via heap2, and tableam_parted_c_heap2 via heap.
> 
> But for tableam_parted_a_heap2 tableam_parted_b_heap2 the answer isn't
> quite as clear.  I think it'd both be sensible for new partitions to
> inherit the AM from the root, but it'd also be sensible to use the
> current default.

Given that many people expected this behavior to be the sane one in other
cases that came up, +1 to go this way.

Thanks,
Amit