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	id AA16562; Fri, 10 Apr 92 13:18:55 -0700
Message-Id: <9204102018.AA16562@postgres.Berkeley.EDU>
From: postarch (Postgres Mailing Archive)
Subject: Re: deferred trigger
To: postgres@postgres.berkeley.edu
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Reply-To: mer@postgres.berkeley.edu
In-Reply-To: Your message of "Tue, 07 Apr 92 10:32:02 PDT."
             <9204071732.AA01208@postgres.Berkeley.EDU> 
Date: Fri, 10 Apr 92 13:18:23 PDT

you write:

> I want to model deferred triggers by the use of the PRS2 rule system.
> Therefore I need a mechanism that some rules are activated during
> a transaction until the command  *end transaction* and then to
> activate further rules which also refer to operations done
> during the transaction.
> 
> Does anybody have any experience with deferred trigger (rules)
> in POSTGRES? Are there any investigations to support
> such rules?

I got the following from Spyros (the ex-OFFICIAL POSTGRES RULES EXPERT)...


  Well, in principle it is possible, all you have to do is look at
  ... [ Spryos' PhD thesis ] ...

  Somewhere in the last chapter I describe how the already existing system
  *with minor extensions* can be used to provide deferred triggers.
  The keyword here is *minor extensions*, which means
  
      a) the postgres code HAS to be changed
      b) I *hope* that the changes wouldn't be too many & difficult
         (just the usual 3 lines of code...)
  
  So, the answer is no, you can not use the current postgres rule system for
  deferred triggers. Pitty!... :-(

  -sp

Jeff Meredith
mer@postgres.berkeley.edu