Re: [HACKERS] Arbitrary tuple size

From: Philip Warner <pjw(at)rhyme(dot)com(dot)au>
To: The Hermit Hacker <scrappy(at)hub(dot)org>, Vadim Mikheev <vadim(at)krs(dot)ru>
Cc: Bruce Momjian <maillist(at)candle(dot)pha(dot)pa(dot)us>, t-ishii(at)sra(dot)co(dot)jp, pgsql-hackers(at)postgreSQL(dot)org
Subject: Re: [HACKERS] Arbitrary tuple size
Date: 1999-07-28 12:33:32
Message-ID: 3.0.5.32.19990728223332.00b21150@mail.rhyme.com.au
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At 09:04 28/07/99 -0300, The Hermit Hacker wrote:
>On Fri, 9 Jul 1999, Vadim Mikheev wrote:
>
>>
>> Bruce Momjian wrote:
>> >
>> > > Bruce Momjian wrote:
>> > > >
>> > > > If we get wide tuples, we could just throw all large objects into one
>> > > > table, and have an on it. We can then vacuum it to compact space,
etc.
>> > >
>> > > Storing 2Gb LO in table is not good thing.
>> > >
>> > > Vadim
>> > >
>> >
>> > Ah, but we have segemented tables now. It will auto-split at 1 gig.
>>
>> Well, now consider update of 2Gb row!
>> I worry not due to non-overwriting but about writing
>> 2Gb log record to WAL - we'll not be able to do it, sure.
>
>What I'm kinda curious about is *why* you would want to store a LO in the
>table in the first place? And, consequently, as Bruce had
>suggested...index it? Unless something has changed recently that I
>totally missed, the only time the index would be used is if a query was
>based on a) start of string (ie. ^<string>) or b) complete string (ie.
>^<string>$) ...
>
>So what benefit would an index be on a LO?
>

Some systems (Dec RDB) won't even let you index the contents of an LO.
Anyone know what other systems do?

Also, to repeat question from an earlier post: is there a plan for the BLOB
implementation that is available for comment/contribution?

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