Re: Adding more memory = hugh cpu load

On 10/11/2011 04:57 AM, Leonardo Francalanci wrote:
> In fact, shouldn't those things be explained in the "WAL
> Configuration" section
> of the manual? It looks as important as configuring Postgresql itself...
> And: that applies to Linux. What about other OS, such as Solaris and FreeBSD?
>

There's at least 10 pages of stuff about this floating around my book,
including notes on the similar Solaris and FreeBSD parameters to tune.

As for why that's not in the manual instead, two reasons.  The
PostgreSQL manual doesn't get too deep into things like operating system
adjustments for performance.  It's big enough without that, and any
information that would be added is likely to get out of sync with new OS
releases.  This project doesn't want to take on the job of documenting
every twist there.  My book is less than a year old, and there's already
some material on this topic that's turning obsolete due to Linux kernel
changes.  The PostgreSQL manual is shooting to still be relevant for
much longer than that.

Second, making an addition to the manual is the hardest possible way to
document things.  The docbook toolchain used is picky and fragile to
malformed additions.  And you can't get anything added there without
passing through a series of people who will offer feedback of some sort;
usually valuable, but still time consuming to process.  Things need to
asked quite frequently before it's worth the trouble.  I did a few blog
entries and mailing list posts about this earlier this year, and that
was as much documentation as I could justify at the time.  If there's a
user-visible behavior changes here, that's the point where an update to
the manual would be in order.

--
Greg Smith   2ndQuadrant US    greg@2ndQuadrant.com   Baltimore, MD
PostgreSQL Training, Services, and 24x7 Support  www.2ndQuadrant.us