Re: [HACKERS] GSoC 2017: weekly progress reports (week 4) and patchfor hash index - Mailing list pgsql-hackers

From Alexander Korotkov
Subject Re: [HACKERS] GSoC 2017: weekly progress reports (week 4) and patchfor hash index
Date
Msg-id CAPpHfdsCe0_saXKdGXeugjJ6_y8UARAcPjT2ApRpVPCqQ4B3-Q@mail.gmail.com
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In response to Re: [HACKERS] GSoC 2017: weekly progress reports (week 4) and patchfor hash index  (Thomas Munro <thomas.munro@enterprisedb.com>)
Responses Re: [HACKERS] GSoC 2017: weekly progress reports (week 4) and patchfor hash index
List pgsql-hackers
On Fri, Sep 8, 2017 at 4:07 AM, Thomas Munro <thomas.munro@enterprisedb.com> wrote:
Hi Shubham,

On Tue, Jun 27, 2017 at 9:21 PM, Shubham Barai <shubhambaraiss@gmail.com> wrote:
> If these two hash keys (78988658 and 546789888) mapped to the same bucket, this will result in false serialization failure.
> Please correct me if this assumption about false positives is wrong.

I wonder if there is an opportunity to use computed hash values
directly in predicate lock tags, rather than doing it on the basis of
buckets.  Perhaps I'm missing something important about the way that
locks need to escalate that would prevent that from working.

+1,
Very nice idea!  Locking hash values directly seems to be superior over locking hash index pages.
Shubham, do you have any comment on this?

------
Alexander Korotkov
Postgres Professional: http://www.postgrespro.com
The Russian Postgres Company

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