Horton

Re: [HACKERS] [PATCH] pageinspect function to decode infomasks

Alvaro Herrera <alvherre@2ndquadrant.com>

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From: Alvaro Herrera <alvherre@2ndquadrant.com>
To: Michael Paquier <michael@paquier.xyz>
Cc: Amit Kapila <amit.kapila16@gmail.com>, Masahiko Sawada <sawada.mshk@gmail.com>, Craig Ringer <craig@2ndquadrant.com>, Ashutosh Sharma <ashu.coek88@gmail.com>, Julien Rouhaud <rjuju123@gmail.com>, Peter Geoghegan <pg@bowt.ie>, PostgreSQL Hackers <pgsql-hackers@postgresql.org>, Abhijit Menon-Sen <ams@2ndquadrant.com>, Peter Eisentraut <peter.eisentraut@2ndquadrant.com>, Pavan Deolasee <pavan.deolasee@2ndquadrant.com>
Date: 2019-09-13T11:49:50Z
Lists: pgsql-hackers 
On 2019-Sep-13, Michael Paquier wrote:

> Attached is a patch to fix your suggestions.  This also removes the
> use of HEAP_XMAX_IS_LOCKED_ONLY which did not make completely sense
> either as a "raw" flag.  While on it, the order of the flags can be
> improved to match more the order of htup_details.h

A thought I had as I fell asleep last night is to include the derivate
flags in a separate output column altogether.  So
heap_tuple_infomask_flags() could be made to return two columns, one
with the straight one-flag-per-bit, and another one with the compound
flags.  That way we always have the raw ones available, and we avoid any
confusion about strange cases such as LOCK_UPGRADED and IS_LOCKED_ONLY.

-- 
Álvaro Herrera                https://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services

Commits

  1. Redesign pageinspect function printing infomask bits

  2. Add to pageinspect function to make t_infomask/t_infomask2 human-readable

  3. Improve documentation of pageinspect

  4. Improve pageinspect module