Re: [HACKERS] systable_getnext_ordered - Mailing list pgsql-novice

From yamt@mwd.biglobe.ne.jp (YAMAMOTO Takashi)
Subject Re: [HACKERS] systable_getnext_ordered
Date
Msg-id 20110201083502.9215B19D0AE@mail.netbsd.org
Whole thread Raw
In response to Re: [HACKERS] systable_getnext_ordered  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-novice
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
>
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