Re: [HACKERS] Runtime Partition Pruning

On 7 April 2018 at 10:45, David Rowley <david(dot)rowley(at)2ndquadrant(dot)com> wrote:
> I'm looking over the rebased patches now.

I've made a complete read of 0001 and 0002 so far.

Your rebase looks fine.

After the complete read, I only have the following comments:

0001:

1. missing "the" before "partition key":

* Extract Params matching partition key and record if we got any.

2. Is this the property name we're going to stick with:

ExplainPropertyInteger("Subplans Pruned", NULL, nplans - nsubnodes, es);

Other ideas are: "Subplans Removed"

3. In the following comment I've used the word "hierarchy", but maybe
we need to add the word "flattened" before it.

* PartitionPruning - Encapsulates a hierarchy of PartitionRelPruning

4. Comment mentions "after init plan", but really we can only know the
value of an exec param during actual execution. So:

* Parameters that are safe to be used for partition pruning. execparams
* are not safe to use until after init plan.

maybe better as:

* Parameters that are safe to be used for partition pruning. execparams
* are not safe to use until the executor is running.

0002:

Looks fine. But if I was committing this, to give me confidence, I'd
want to know how the left_most_one table was generated.

I used:

#include <stdio.h>

int main(void)
{
int i = 1;

printf("0, ");
while (i < 256)
{
printf("%d, ", 31 - __builtin_clz(i));
if ((i & 0xf) == 0xf)
putchar('\n');
i++;
}
return 0;
}

Continuing to read 0003 and 0004 now.

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