Re: Do we actually need an ItemId array on nbtree pages containing fixed-width tuples?

From: Andrey Borodin <x4mmm(at)yandex-team(dot)ru>
To: Peter Geoghegan <pg(at)bowt(dot)ie>
Cc: PostgreSQL Hackers <pgsql-hackers(at)lists(dot)postgresql(dot)org>
Subject: Re: Do we actually need an ItemId array on nbtree pages containing fixed-width tuples?
Date: 2017-12-04 06:11:31
Message-ID: 92DDB751-189E-4AA2-9703-C94371B6A98D@yandex-team.ru
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-hackers

Hi, Peter!

> 4 дек. 2017 г., в 4:55, Peter Geoghegan <pg(at)bowt(dot)ie> написал(а):
> Thoughts?

I like the idea of more compact B-tree.
Chances are that I didn't understood all your ideas.

But ItemId's let you insert a tuple among two existing tuples without data movement. New tuple is places wherever free space starts. You just shift bytes in ItemId array.
And you always have to insert tuple in specific position, since B-tree relies on tuple order.

Best regards, Andrey Borodin.

In response to

Responses

Browse pgsql-hackers by date

  From Date Subject
Next Message Amit Kapila 2017-12-04 06:33:35 Re: Would a BGW need shmem_access or database_connection to enumerate databases?
Previous Message Michael Paquier 2017-12-04 05:58:59 Re: [HACKERS] Vacuum: allow usage of more than 1GB of work mem