Horton

Re: Making all nbtree entries unique by having heap TIDs participate in comparisons

Peter Geoghegan <pg@bowt.ie>

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From: Peter Geoghegan <pg@bowt.ie>
To: Heikki Linnakangas <hlinnaka@iki.fi>
Cc: Dmitry Dolgov <9erthalion6@gmail.com>, Robert Haas <robertmhaas@gmail.com>, Peter Eisentraut <peter.eisentraut@2ndquadrant.com>, PostgreSQL Hackers <pgsql-hackers@postgresql.org>, Alexander Korotkov <a.korotkov@postgrespro.ru>, Thomas Munro <thomas.munro@enterprisedb.com>, Claudio Freire <klaussfreire@gmail.com>, Anastasia Lubennikova <a.lubennikova@postgrespro.ru>, "Andrey V. Lepikhov" <a.lepikhov@postgrespro.ru>
Date: 2019-03-19T23:15:39Z
Lists: pgsql-hackers 
On Mon, Mar 18, 2019 at 10:17 AM Peter Geoghegan <pg@bowt.ie> wrote:
> The big difference is that you make the possible call to
> _bt_stepright() conditional on this being a checkingunique index --
> the duplicate code is indented in that branch of _bt_findsplitloc().
> Whereas I break early in the loop when "checkingunique &&
> heapkeyspace".

Heikki and I discussed this issue privately, over IM, and reached
final agreement on remaining loose ends. I'm going to use his code for
_bt_findsplitloc(). Plan to push a final version of the first four
patches tomorrow morning PST.

-- 
Peter Geoghegan

Commits

  1. Add "split after new tuple" nbtree optimization.

  2. Add nbtree high key "continuescan" optimization.

  3. Allow amcheck to re-find tuples using new search.

  4. Consider secondary factors during nbtree splits.

  5. Make heap TID a tiebreaker nbtree index column.

  6. Refactor nbtree insertion scankeys.

  7. Redesign the partition dependency mechanism.

  8. Avoid unnecessary palloc overhead in _bt_first(). The temporary