agora inbox for postgres@postgres.berkeley.edu  

help / color / mirror / Atom feed

From: Wolf-D. Ihlenfeldt <wolf@molout.tutkie.tut.ac.jp>
To: postgres@postgres.Berkeley.EDU
Subject: Tuple-Functions on variable tables ?
Date: Fri, 30 Sep 94 13:45:19 jst
Message-ID: <9409300445.AA07197@molout.tutkie.tut.ac.jp> (raw)


I need to make some pretty complicated comparisons between
tuples. The tuples may be from the same or different tables.
I defined a user function, which works fine for the tuples
it is defined for, i.e.

   my_func(class1,class2)
  
works fine if the function is defined as

  define function my_func (language = "c", returntype = bool,
   trusted="t", percall_cpu = "costly!!!")
   arg is (class1,class2) as "/path/myfunc.so"

But how to I formulate a query with
   my_func(class1,class1)
   
or

   my_func(class3,class4)

where class3 and 4 may have a slightly different structure, but do
contain the fields used in the function for the comparison.
I have not found a way to pass classes which are different to
those in the prototype htrough the parser. Is there some way
to do this ? And if this is possible, how about using 
different classes with operators bound to the functio, i.e.

  define operator = (arg1=class1,arg2=class2,procedure=my_func,
  restrict=eqsel,join=eqsel)

??

Any help is appreciated.

WDI


==============================================================================
   To add/remove yourself to/from the POSTGRES mailing list: send mail with 
   the subject line ADD or DEL to "postgres-request@postgres.Berkeley.EDU"

   If this fails, send mail to "post_questions@postgres.Berkeley.EDU" and
   a human will deal with it.  DO NOT post to the "postgres" mailing list.
==============================================================================

reply

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Reply to all the recipients using the --to and --cc options:
  reply via email

  To: postgres@postgres.berkeley.edu
  Cc: wolf@molout.tutkie.tut.ac.jp
  Subject: Re: Tuple-Functions on variable tables ?
  In-Reply-To: <9409300445.AA07197@molout.tutkie.tut.ac.jp>

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

This inbox is served by agora; see mirroring instructions
for how to clone and mirror all data and code used for this inbox