Обсуждение: rule plan too big (fwd)

---------- Forwarded message ----------
Date: Thu, 3 Jun 1999 10:03:56 -0500 (CDT)
From: Phil DiCorpo <pd3@wuerl.wustl.edu>
To: pgsql-sql@postgresql.org
Subject: rule plan too big


I'm trying to create a relatively large view and I'm getting the
"DefineQueryRewrite: rule plan too big" error.  Is this a bug in Postgres
that currently has no workaround, or is there something I can do.  A
previous posting mentioned changing the blocksize.  I thought I made this
change correctly, but it did not get rid of the error.  Any help would be
much appreciated.

Phil

> I'm trying to create a relatively large view and I'm getting the
> "DefineQueryRewrite: rule plan too big" error.  Is this a bug in Postgres
> that currently has no workaround, or is there something I can do.  A
> previous posting mentioned changing the blocksize.  I thought I made this
> change correctly, but it did not get rid of the error.  Any help would be
> much appreciated.

    Currently  there  is  no other workaround than increasing the
    overall database blocksize until  it  fits.  At  the  time  I
    mentioned  changing the rule plan (and qualification) storage
    to be able to split over tuples there was discussion about  a
    general  tuple split capability, which would have solved this
    problem silently. Unfortunately this general solution did not
    incarnate for v6.5.

    I've  also played around with another data type which uses an
    internal  format  that  is  a  simple,   byte   oriented   lz
    compression.   Using   that  on  rule  strings  approximately
    compresses with rates of 40-70% (better  on  large  rules  ==
    complex views).

    For  now I'm planning to wait until v6.5 is released and then
    make a feature patch where the  rule  plans  will  be  stored
    compressed.  That will lower the problem (not entirely fixing
    it) and offer the new compressed type for other purposes too.

    *******************************************************
    * WE STILL NEED THE GENERAL TUPLE SPLIT CAPABILITY!!! *
    *******************************************************

    I  vote  for  sticking  this  onto  the  TODO  and  make it a
    permanent show-stopper  for  version  7.0.  NO  v7.0  without
    unlimited tuple size!  I know that this is about a year or so
    ahead :-)


Jan

--

#======================================================================#
# It's easier to get forgiveness for being wrong than for being right. #
# Let's break this rule - forgive me.                                  #
#========================================= wieck@debis.com (Jan Wieck) #

>     *******************************************************
>     * WE STILL NEED THE GENERAL TUPLE SPLIT CAPABILITY!!! *
>     *******************************************************
> 
>     I  vote  for  sticking  this  onto  the  TODO  and  make it a
>     permanent show-stopper  for  version  7.0.  NO  v7.0  without
>     unlimited tuple size!  I know that this is about a year or so
>     ahead :-)
> 

Already on TODO:
* allow chaining of pages to allow >8k tuples
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