Hello,

I'm running into what appears to be some hard coded limits of postgres.
I've got a table with with a text column that I need to insert large 
amounts of text into.  I quickly found these two things out:  

First, the MAX_QUERY_SIZE which is BLCKSZ*2 (or 16384 bytes), prevents
me from from running the query since my query is much larger than 16384 i
bytes.  After discovering this, I decided to create a test query just
smaller than 16384 to see what would happen.  

The second query returns "Tuple is too big: size 12508".  I didn't bother
to look into this one because I'd probably spend a lot of time looking,
instead I am bringing the issue here.

I haven't done any development work on postgres and don't want 
to get involved in doing so before discussing it here and making sure that 
my efforts won't be in vain.  Without looking at the code, I expect this
problem is not *simple* to fix.  I'm operating on the assumption that
tuple sizes cannot be changed very easily.  Even if they could, a bigger
problem is probably the MAX_QUERY_SIZE.  Simply increasing the MAX_QUERY_SIZE
will only address a short term problem, and there is a practicle limit
to the size it can be increased.  Idealy, some sort of dynamic query buffer
would be better but that likely challanges the way the communication
between the client and server works.

So, has anyone looked into this limitation?  Is it something that the
development team wants to be addressed?  If this is a know problem, is 
there some sort of agreement on how it should be solved?  If so, is
someone working on it?  If not, possible I could help.  

Over the last 9 months, I've been using postgres more and more.  It's gotten
to the point where our project is becoming quite dependent on it.  I am 
quite happy with the software and want to stick with it.  I've run into 
several minor things this year that I have been able to avoid, but this 
one may be a show stopper.  Rather than ditch this fine software, I'd
rather help out if the help is wanted and I am capible of giving it the
time required.

More details on the problem I am having:
	Redhat 6.0 / x86
	Postgres 6.5.1
	Inserts tried with psql and libpg via Perl DBD/DBI

-Brian

Wed, 27 Oct 1999 14:25:18 -0400
Brian Hirt <bhirt@mobygames.com>
text datatype and tuple size limits.
As far as I could follow it, the query size limit is all but gone, and it
will be for sure in 7.0. Regarding the tuple size limit, we are still
looking for volunteers to tackle that. You should find relevant messages
on this list a few days back.

	-Peter

On Wed, 27 Oct 1999, Brian Hirt wrote:

> I'm running into what appears to be some hard coded limits of postgres.
> I've got a table with with a text column that I need to insert large 
> amounts of text into.  I quickly found these two things out:  
> 
> First, the MAX_QUERY_SIZE which is BLCKSZ*2 (or 16384 bytes), prevents
> me from from running the query since my query is much larger than 16384 i
> bytes.  After discovering this, I decided to create a test query just
> smaller than 16384 to see what would happen.  
> 
> The second query returns "Tuple is too big: size 12508".  I didn't bother
> to look into this one because I'd probably spend a lot of time looking,
> instead I am bringing the issue here.


-- 
Peter Eisentraut                  Sernanders vaeg 10:115
peter_e@gmx.net                   75262 Uppsala
http://yi.org/peter-e/            Sweden


Thu, 28 Oct 1999 12:17:01 +0200 (MET DST)
Peter Eisentraut <e99re41@DoCS.UU.SE>
Re: [HACKERS] text datatype and tuple size limits.