Re: [HACKERS] MAX Query length

From: wieck(at)debis(dot)com (Jan Wieck)
To: tgl(at)sss(dot)pgh(dot)pa(dot)us (Tom Lane)
Cc: frankpit(at)pop(dot)dn(dot)net, pgsql-hackers(at)postgreSQL(dot)org
Subject: Re: [HACKERS] MAX Query length
Date: 1999-07-15 08:36:16
Message-ID: m114h04-0003kMC@orion.SAPserv.Hamburg.dsh.de
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Tom Lane wrote:

>
> Bernard Frankpitt <frankpit(at)pop(dot)dn(dot)net> writes:
> > Tom Lane wrote:
> >> Sure: you want to be able to INSERT a tuple of maximum size. In the
> >> absence of dynamically sized text buffers, a reasonable estimate of
> >> the longest INSERT command of interest is going to depend on BLCKSZ.
>
> > Perhaps it would be a good idea to increase
> > the multiplier in
> > #define MAX_QUERY_SIZE (BLCKSZ * 2)
> > to something larger than 2.
>
> This entire chain of logic will fall to the ground anyway once we support
> tuples larger than a disk block, which I believe is going to happen
> before too much longer. So, rather than argue about what the multiplier
> ought to be, I think it's more productive to just press on with making
> the query buffers dynamically resizable...

Yes, even if we choose to make some other limit (like Vadim
suggested around 64K), a query operating on them could be
much bigger. I already had some progress with a data type
that uses a simple, byte oriented lz compression buffer as
internal representation.

Jan

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