Re: [PERFORM] WAL Optimisation - configuration and usage - Mailing list pgsql-hackers

From Simon Riggs
Subject Re: [PERFORM] WAL Optimisation - configuration and usage
Date
Msg-id 004601c40565$0e848c60$f3bd87d9@LaptopDellXP
Whole thread Raw
In response to Re: [PERFORM] WAL Optimisation - configuration and usage  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-hackers
>Tom Lane
> "Simon Riggs" <simon@2ndquadrant.com> writes:
> > The behaviour I wish to add is:
> > Keep wal_debug as a value between 0 and 16.
> > If =0 then no debug output (default).
> > Use following bitmasks against the value
> > Mask 1 = XLOG Checkpoints get logged
> > Mask 2 = Archive API calls get logged
> > Mask 4 = Transaction - commits get logged
> > Mask 8 = Flush & INSERTs get logged
> 
> I see no value in reverting Neil's change.  The above looks way too
much
> like old-line assembler-programmer thinking to me, anyway.  Why not
> invent a separate, appropriately named boolean variable for each thing
> you want to control?  Even C programmers manage to avoid doing the
sort
> of mental arithmetic that the above would force onto DBAs.
> 
> As for whether it should be #ifdef'd or not, I'd have no objection to
> turning WAL_DEBUG on by default in pg_config_manual.h for the duration
> of PITR development.  One should not however confuse short-term
> debugging needs with features that the average user is going to need
> indefinitely.  (It was not too long ago that there was still debugging
> code for btree index building in there, for crissakes.)

...erm, I guess you didn't like that one then? ;}

> As for whether it should be #ifdef'd or not, I'd have no objection to
> turning WAL_DEBUG on by default in pg_config_manual.h for the duration
> of PITR development.  

Yes OK, thank you.

> Why not
> invent a separate, appropriately named boolean variable for each thing
> you want to control?

Yes, OK, will do.

Best Regards, Simon Riggs



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