Re: speeding up planning with partitions

[Justin Pryzby]

On Fri, Feb 22, 2019 at 09:45:38PM +0900, Amit Langote wrote:
> I have updated the inheritance expansion patch.
> 
> Patch 0001 rewrites optimizer/utils/inherit.c, so that it allows

Thanks for your continued work on this.

I applied v23 patch and imported one of our customers' schema, and ran explain
on a table with 210 partitions.  With patch applied there are 10x fewer system
calls, as intended.

with patch:
    173 pread64
     76 lseek
     47 open
     38 brk

without patch:
   1276 lseek
    693 pread64
    647 open
    594 brk

> +             if (IS_SIMPLE_REL(rel1) && child_rel1 == NULL)
> +                     child_rel1 = build_dummy_partition_rel(root, rel1, 
> baserel1,
> +                                                                             
>                    cnt_parts);
> +             if (IS_SIMPLE_REL(rel1) && child_rel2 == NULL)
> +                     child_rel2 = build_dummy_partition_rel(root, rel2, 
> baserel2,
> +                                                                             
>                    cnt_parts);

Should 2nd "if" say IS_SIMPLE_REL(rel2) ?

Justin