Re: [HACKERS] Arbitrary tuple size - Mailing list pgsql-hackers

From Philip Warner
Subject Re: [HACKERS] Arbitrary tuple size
Date
Msg-id 3.0.5.32.19990728223332.00b21150@mail.rhyme.com.au
Whole thread Raw
In response to Re: [HACKERS] Arbitrary tuple size  (The Hermit Hacker <scrappy@hub.org>)
List pgsql-hackers
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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