From: Jim C. Nasby <jnasby@pervasive.com>
To: Christopher Browne <cbbrowne@acm.org>
Cc: pgsql-general@postgresql.org
Cc: pgsql-docs@postgresql.org
Subject: Re: [GENERAL] TOAST not working
Date: Sat, 10 Jun 2006 21:12:15 -0500
Message-ID: <20060611021215.GC83625@pervasive.com> (raw)
In-Reply-To: <87bqt03efl.fsf@wolfe.cbbrowne.com>
References: <1149944622.15368.38.camel@vaio1linux>
<87bqt03efl.fsf@wolfe.cbbrowne.com>
On Sat, Jun 10, 2006 at 05:10:06PM -0400, Christopher Browne wrote:
> Centuries ago, Nostradamus foresaw when listman@elkenserver.net (list_man) would write:
> > Can someone tell me if I have to 'enable' TOAST on columns to have it
> > kick in. According to my research, numeric data types are toastable.
>
> TOAST is only used on individual columns that exceed 8K in size.
>
> The only way you'll be TOASTing numeric columns is if they are
> individually defined to occupy > 8192 bytes.
Actually, it's BLCKSZ/4. From
http://www.postgresql.org/docs/8.1/interactive/storage-toast.html:
"The TOAST code is triggered only when a row value to be stored in a
table is wider than BLCKSZ/4 bytes (normally 2Kb)."
BTW, 'row value' seems a bit prone to confusion (could be interpreted as
the row itself). It'd probably be better to say 'field'. Barring
objections, I'll submit a patch.
--
Jim C. Nasby, Sr. Engineering Consultant jnasby@pervasive.com
Pervasive Software http://pervasive.com work: 512-231-6117
vcard: http://jim.nasby.net/pervasive.vcf cell: 512-569-9461
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To: pgsql-docs@postgresql.org
Cc: jnasby@pervasive.com, cbbrowne@acm.org, pgsql-general@postgresql.org
Subject: Re: [GENERAL] TOAST not working
In-Reply-To: <20060611021215.GC83625@pervasive.com>
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