Horton

Re: Patch: Write Amplification Reduction Method (WARM)

Peter Geoghegan <pg@bowt.ie>

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From: Peter Geoghegan <pg@bowt.ie>
To: Robert Haas <robertmhaas@gmail.com>
Cc: Bruce Momjian <bruce@momjian.us>, Pavan Deolasee <pavan.deolasee@gmail.com>, Amit Kapila <amit.kapila16@gmail.com>, Alvaro Herrera <alvherre@2ndquadrant.com>, Jaime Casanova <jaime.casanova@2ndquadrant.com>, Haribabu Kommi <kommi.haribabu@gmail.com>, Tomas Vondra <tomas.vondra@2ndquadrant.com>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2017-03-21T17:08:04Z
Lists: pgsql-hackers 
On Tue, Mar 21, 2017 at 10:04 AM, Robert Haas <robertmhaas@gmail.com> wrote:
> I think that's a good question.  I previously expressed similar
> concerns.  On the one hand, it's hard to ignore the fact that, in the
> cases where this wins, it already buys us a lot of performance
> improvement.  On the other hand, as you say (and as I said), it eats
> up a lot of bits, and that limits what we can do in the future.  On
> the one hand, there is a saying that a bird in the hand is worth two
> in the bush.  On the other hand, there is also a saying that one
> should not paint oneself into the corner.

Are we really saying that there can be no incompatible change to the
on-disk representation for the rest of eternity? I can see why that's
something to avoid indefinitely, but I wouldn't like to rule it out.

-- 
Peter Geoghegan

Commits

  1. Implement SortSupport for macaddr data type

  2. Simplify check of modified attributes in heap_update

  3. Remove direct uses of ItemPointer.{ip_blkid,ip_posid}

  4. Fix CatalogTupleInsert/Update abstraction for case of shared indstate.

  5. Provide CatalogTupleDelete() as a wrapper around simple_heap_delete().

  6. Band-aid fix for incorrect use of view options as StdRdOptions.

  7. Update visibility map in the second phase of vacuum.

  8. Avoid having two copies of the HOT-chain search logic.

  9. Postgres95 1.01 Distribution - Virgin Sources