Re: [HACKERS] path toward faster partition pruning

On 4 April 2018 at 19:04, Amit Langote <Langote_Amit_f8(at)lab(dot)ntt(dot)co(dot)jp> wrote:
> On 2018/04/04 14:42, Amit Langote wrote:
>> Attached v48.
>
> I had forgotten to remove the static_pruning parameter I had added in the
> v47, because it is no longer used. Static pruning now occurs even if a
> step contains all Params, in which case each of
> get_matching_hash/list/range_bounds() functions returns offsets of all
> non-null datums, because the Params cannot be resolved to actual values
> during static pruning.

Thanks for updating. I've made a pass over v49 and I didn't find very
much wrong with it.

The only real bug I found was a missing IsA(rinfo->clause, Const) in
the pseudoconstant check inside
generate_partition_pruning_steps_internal.

Most of the changes are comment fixes with a few stylistic changes
thrown which are pretty much all there just to try to shrink the code
a line or two or reduce indentation.

I feel pretty familiar with this code now and assuming the attached is
included I'm happy for someone else, hopefully, a committer to take a
look at it.

I'll leave the following notes:

1. Still not sure about RelOptInfo->has_default_part. This flag is
only looked at in generate_partition_pruning_steps. The RelOptInfo and
the boundinfo is available to look at, it's just that the
partition_bound_has_default macro is defined in partition.c rather
than partition.h.

2. Don't really like the new isopne variable name. It's not very
simple to decode, perhaps something like is_not_eq is better?

3. The part of the code I'm least familiar with is
get_steps_using_prefix_recurse(). I admit to not having had time to
fully understand that and consider ways to break it.

Marking as ready for committer.

--
David Rowley http://www.2ndQuadrant.com/
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