Horton

Re: making relfilenodes 56 bits

Robert Haas <robertmhaas@gmail.com>

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From: Robert Haas <robertmhaas@gmail.com>
To: Andres Freund <andres@anarazel.de>
Cc: Dilip Kumar <dilipbalaut@gmail.com>, Heikki Linnakangas <hlinnaka@iki.fi>, Thomas Munro <thomas.munro@gmail.com>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2022-07-03T14:32:21Z
Lists: pgsql-hackers 
On Sat, Jul 2, 2022 at 3:29 PM Andres Freund <andres@anarazel.de> wrote:
> Why did you choose a quite small value for VAR_RFN_PREFETCH? VAR_OID_PREFETCH
> is 8192, but you chose 64 for VAR_RFN_PREFETCH?

As Dilip mentioned, I suggested a lower value. If that's too low, we
can go higher, but I think there is value in not making this
excessively large. Somebody somewhere is going to have a database
that's crash-restarting like mad, and I don't want that person to run
through an insane number of relfilenodes for no reason. I don't think
there are going to be a lot of people creating thousands upon
thousands of relations in a short period of time, and I'm not sure
that it's a big deal if those who do end up having to wait for a few
extra xlog flushes.

-- 
Robert Haas
EDB: http://www.enterprisedb.com

Commits

  1. Fix typos in comments, code and documentation

  2. Increase width of RelFileNumbers from 32 bits to 56 bits.

  3. Move RelFileNumber declarations to common/relpath.h.

  4. Include RelFileLocator fields individually in BufferTag.

  5. Convert macros to static inline functions (buf_internals.h)

  6. Remove the restriction that the relmap must be 512 bytes.

  7. Change internal RelFileNode references to RelFileNumber or RelFileLocator.

  8. Reorder subskiplsn in pg_subscription to avoid alignment issues.

  9. Fix DROP {DATABASE,TABLESPACE} on Windows.

  10. Restructure smgr API as per recent proposal. smgr no longer depends on