Re: Hash Indexes

On Thu, Nov 3, 2016 at 6:25 AM, Amit Kapila <amit(dot)kapila16(at)gmail(dot)com> wrote:
>> + nblkno = _hash_get_newblk(rel, pageopaque);
>>
>> I think this is not a great name for this function. It's not clear
>> what "new blocks" refers to, exactly. I suggest
>> FIND_SPLIT_BUCKET(metap, bucket) or OLD_BUCKET_TO_NEW_BUCKET(metap,
>> bucket) returning a new bucket number. I think that macro can be
>> defined as something like this: bucket + (1 <<
>> (fls(metap->hashm_maxbucket) - 1)).
>>
>
> I think such a macro would not work for the usage of incomplete
> splits. The reason is that by the time we try to complete the split
> of the current old bucket, the table half (lowmask, highmask,
> maxbucket) would have changed and it could give you the bucket in new
> table half.

Can you provide an example of the scenario you are talking about here?

--
Robert Haas
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