Re: [NOVICE] systable_getnext_ordered

YAMAMOTO Takashi <yamt@mwd.biglobe.ne.jp>

From: yamt@mwd.biglobe.ne.jp (YAMAMOTO Takashi)
To: tgl@sss.pgh.pa.us
Cc: pgsql-novice@postgresql.org, pgsql-hackers@postgresql.org
Date: 2011-02-01T08:35:02Z
Lists: pgsql-hackers
hi,

thanks for taking a look.

> yamt@mwd.biglobe.ne.jp (YAMAMOTO Takashi) writes:
>> the attached patch is to avoid unnecessary detoast'ing and EOF marker pages
>> when possible.  does it make sense?
> 
> The blob page size is already chosen not to allow for out-of-line
> storage, not to mention that pg_largeobject doesn't have a TOAST table.
> So I think avoiding detoasting is largely a waste of time.

doesn't detoasting involve decompression?

> I'm
> unexcited about the other consideration too --- it looks to me like it
> just makes truncation slower, more complicated, and hence more
> bug-prone, in return for a possible speedup that probably nobody will
> ever notice.

slower?  it depends, i guess.

my primary motivation of that part of the patch was to save some space for
certain workloads.  (besides that, leaving unnecessary rows isn't neat,
but it might be a matter of taste.)

YAMAMOTO Takashi

> 
> 			regards, tom lane
> 
> -- 
> Sent via pgsql-novice mailing list (pgsql-novice@postgresql.org)
> To make changes to your subscription:
> http://www.postgresql.org/mailpref/pgsql-novice