Re: [HACKERS] MAX Query length - Mailing list pgsql-hackers

From wieck@debis.com (Jan Wieck)
Subject Re: [HACKERS] MAX Query length
Date
Msg-id m114h04-0003kMC@orion.SAPserv.Hamburg.dsh.de
Whole thread Raw
In response to Re: [HACKERS] MAX Query length  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-hackers
Tom Lane wrote:

>
> Bernard Frankpitt <frankpit@pop.dn.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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