Re: checkpointer continuous flushing - Mailing list pgsql-hackers

From Alvaro Herrera
Subject Re: checkpointer continuous flushing
Date
Msg-id 20160120151624.GA298712@alvherre.pgsql
Whole thread Raw
In response to Re: checkpointer continuous flushing  (Andres Freund <andres@anarazel.de>)
Responses Re: checkpointer continuous flushing  (Andres Freund <andres@anarazel.de>)
List pgsql-hackers
Andres Freund wrote:

> The relevant thread is at
> http://archives.postgresql.org/message-id/CA%2BTgmoaCr3kDPafK5ygYDA9mF9zhObGp_13q0XwkEWsScw6h%3Dw%40mail.gmail.com
> what I didn't remember is that I voiced concern back then about exactly this:
> http://archives.postgresql.org/message-id/201112011518.29964.andres%40anarazel.de
> ;)

Interesting.  If we consider for a minute that part of the cause for the
slowdown is slowness in pg_clog, maybe we should reconsider the initial
decision to flush as quickly as possible (i.e. adopt a strategy where
walwriter sleeps a bit between two flushes) in light of the group-update
feature for CLOG being proposed by Amit Kapila in another thread -- it
seems that these things might go hand-in-hand.

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



pgsql-hackers by date:

Previous
From: Craig Ringer
Date:
Subject: Re: WIP: Failover Slots
Next
From: Konstantin Knizhnik
Date:
Subject: Re: Proposal for UPDATE: do not insert new tuple on heap if update does not change data