Re: CLUSTER, reform_and_rewrite_tuple(), and parallelism - Mailing list pgsql-hackers

From Andres Freund
Subject Re: CLUSTER, reform_and_rewrite_tuple(), and parallelism
Date
Msg-id 20160818002006.s7wko4pq3vurozaw@alap3.anarazel.de
Whole thread Raw
In response to Re: CLUSTER, reform_and_rewrite_tuple(), and parallelism  (Alvaro Herrera <alvherre@2ndquadrant.com>)
Responses Re: CLUSTER, reform_and_rewrite_tuple(), and parallelism  (Peter Geoghegan <pg@heroku.com>)
List pgsql-hackers
On 2016-08-17 21:17:56 -0300, Alvaro Herrera wrote:
> Peter Geoghegan wrote:
> 
> > This doesn't seem that interesting, but not sure what you're looking for.
> > 
> > I also attach cycles flamegraph.
> 
> I may be blind, but what are those write() calls attributed to
> heap_form_tuple?

libc isn't compiled with -fno-omit-frame-pointer (and even if, it uses
assembly without setup of the frame pointer), so frame pointer based
call graphs are wrong through libc.  The attributions are based on
random stuff in the frame pointer at that point.  You either need to use
dwarf or lbr to get accurate ones.



pgsql-hackers by date:

Previous
From: Alvaro Herrera
Date:
Subject: Re: CLUSTER, reform_and_rewrite_tuple(), and parallelism
Next
From: Ryan Murphy
Date:
Subject: Re: Patch: initdb: "'" for QUOTE_PATH (non-windows)