Horton

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

Heikki Linnakangas <hlinnaka@iki.fi>

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From: Heikki Linnakangas <hlinnaka@iki.fi>
To: Peter Geoghegan <pg@bowt.ie>
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: 2019-03-05T11:37:08Z
Lists: pgsql-hackers

Attachments

I'm looking at the first patch in the series now. I'd suggest that you 
commit that very soon. It's useful on its own, and seems pretty much 
ready to be committed already. I don't think it will be much affected by 
whatever changes we make to the later patches, anymore.

I did some copy-editing of the code comments, see attached patch which 
applies on top of v14-0001-Refactor-nbtree-insertion-scankeys.patch. 
Mostly, to use more Plain English: use active voice instead of passive, 
split long sentences, avoid difficult words.

I also had a few comments and questions on some details. I added them in 
the same patch, marked with "HEIKKI:". Please take a look.

- Heikki

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