Re: increasing the default WAL segment size

Peter Eisentraut <peter.eisentraut@2ndquadrant.com>

From: Peter Eisentraut <peter.eisentraut@2ndquadrant.com>

To: David Steele <david@pgmasters.net>, Robert Haas <robertmhaas@gmail.com>, Stephen Frost <sfrost@snowman.net>, Beena Emerson <memissemerson@gmail.com>

Cc: tushar <tushar.ahuja@enterprisedb.com>, Prabhat Sahu <prabhat.sahu@enterprisedb.com>, Ashutosh Sharma <ashu.coek88@gmail.com>, Jim Nasby <Jim.Nasby@bluetreble.com>, Kuntal Ghosh <kuntalghosh.2007@gmail.com>, Andres Freund <andres@anarazel.de>, "pgsql-hackers@postgresql.org" <pgsql-hackers@postgresql.org>

Date: 2017-03-25T15:36:37Z

Lists: pgsql-hackers

On 3/24/17 19:13, David Steele wrote:
> Behavior for the current default of 16MB is unchanged, and all other 
> sizes go through a logical progression.

Just at a glance, without analyzing the math behind it, this scheme
seems super confusing.

> 
> 1GB:
> 000000010000000000000040
> 000000010000000000000080
> 0000000100000000000000C0
> 000000010000000100000000
> 
> 256GB:
> 
> 000000010000000000000010
> 000000010000000000000020
> 000000010000000000000030
> ...
> 0000000100000000000000E0
> 0000000100000000000000F0
> 000000010000000100000000
> 
> 64GB:
> 
> 000000010000000100000004
> 000000010000000100000008
> 00000001000000010000000C
> ...
> 0000000100000001000000F8
> 0000000100000001000000FC
> 000000010000000100000000


-- 
Peter Eisentraut              http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

Make WAL segment size configurable at initdb time.
- fc49e24fa69a 11.0 landed
Perform only one ReadControlFile() during startup.
- 8356753c212a 11.0 landed
Introduce BYTES unit for GUCs.
- 6e7baa322773 11.0 landed
Remove useless duplicate inclusions of system header files.
- 9e3755ecb2d0 10.0 cited
Refactor other replication commands to use DestRemoteSimple.
- bbd8550bce14 10.0 landed
Add a SHOW command to the replication command language.
- d1ecd539477f 10.0 landed
Add a new DestReceiver for printing tuples without catalog access.
- a84069d93504 10.0 landed
Support fls().
- 4f658dc851a7 9.2.0 cited
Extend yesterday's patch making BLCKSZ and RELSEG_SIZE configurable to also
- cf9f6c8d8e9d 8.4.0 cited
Commit the reasonably uncontroversial parts of J.R. Nield's PITR patch, to
- c3c09be34b6b 8.0.0 cited
XLOG (also known as WAL -:)) Bootstrap/Startup/Shutdown.
- 47937403676d 7.1.1 cited
Transaction log manager core code.
- 30659d43eb73 7.1.1 cited