Re: [HACKERS] path toward faster partition pruning

Hi David.

Thanks for the review.

On 2018/02/21 19:15, David Rowley wrote:
> Thanks for fixing. I made a pass over v31 and only see a few small things:
>
> 1. In get_partitions_for_keys() why is the
> get_partitions_excluded_by_ne_datums call not part of
> get_partitions_for_keys_list?

Hmm, there is a question of where exactly to put the call within
get_partitions_for_keys_list(). At the end would sound like an obvious
answer, but we tend to short-circuit return from that function at various
points, which it seems undesirable to change. So, I left things as is here.

> 2. Still a stray "minoff += 1;" in get_partitions_for_keys_range

I actually found a few and changed them to ++ or --, as applicable.

>
> 3. You're also preferring to minoff--/++, but maxoff -= 1/maxoff += 1;
> would be nice to see the style unified here.

Fixed all as mentioned above.

> 4. "other other"
>
> * that is, each of its fields other other than clauseinfo must be valid before

Fixed.

> 5. "a IS NULL" -> "an IS NULL":
>
> * Based on a IS NULL or IS NOT NULL clause that was matched to a partition

Fixed.

> 6. Can you add a warning in the header comment for
> extract_partition_clauses() to explain "Note: the 'clauses' List may
> be modified inside this function. Callers may like to make a copy of
> important lists before passing them to this function.", or something
> like that...

At least in my patch, extract_partition_clauses() is a local function with
just one caller, but I still don't see any problem with warning the
reader. So, done.

> 7. "null" -> "nulls"
>
> * Only allow strict operators. This will guarantee null are
>
> 8. "dicard" -> "discard"
>
> * contains a <= 2, then because 3 <= 2 is false, we dicard a < 3 as

Fixed.

Please find attached updated patches.

Thanks,
Amit