Re: [HACKERS] Default Partition for Range

Thanks for rebasing.

Range partition review:

1.

There are lot of changes in RelationBuildPartitionDesc(). It was hard to

understand why these changes are needed for default partition. I did not find

any explanation for the same, may be I am missing some discussion? Only

when I looked into it carefully I could understand that these changes are

nothing but optimization for identifying the distinct bounds.

I think it is better to keep the patch for code optimisation/simplification in a

separate patch. I have separated the patch(0001) in attached patches for this

purpose.

2.

+ * For default partition, it returns the negation of the constraints of all

+ * the other partitions.

+ *

+ * If we end up with an empty result list, we return NULL.

We can rephrase the comment as below:

"For default partition, function returns the negation of the constraints of all

the other partitions. If default is the only partition then returns NULL."

3.

@@ -2396,6 +2456,8 @@ make_one_range_bound(PartitionKey key, int index, List *datums, bool lower)

    ListCell   *lc;

    int         i;

+   Assert(datums != NULL);

+

    bound = (PartitionRangeBound *) palloc0(sizeof(PartitionRangeBound));

    bound->index = index;

    bound->datums = (Datum *) palloc0(key->partnatts * sizeof(Datum));

I am not really convinced, why should we have above Assert.

4.

 static List *

-get_qual_for_range(PartitionKey key, PartitionBoundSpec *spec)

+get_qual_for_range(Relation parent, PartitionBoundSpec *spec,

+                  bool for_default)

 {

The addition and the way flag ‘for_default’ is being used is very confusing.

At this moment I am not able to think about a alternate solution to the

way you have used this flag. But will try and see if I can come up with

an alternate approach.

I still need to look at the test, and need to do some manual testing. Will

update here with any findings.

Patches:

0001: Refactoring/simplification of code in RelationBuildPartitionDesc(),

0002: implementation of default range partition by Beena.

Regards,

Jeevan