Re: Proposal for updatable views - Mailing list pgsql-hackers

From Bruce Momjian
Subject Re: Proposal for updatable views
Date
Msg-id 200606161850.k5GIocV13194@candle.pha.pa.us
Whole thread Raw
In response to Proposal for updatable views  (Bernd Helmle <mailings@oopsware.de>)
List pgsql-hackers
URL added to TODO.  I assume there has been no more progress on this patch.

---------------------------------------------------------------------------

Bernd Helmle wrote:
> Hi folks,
> 
> Please find attached a patch that implements SQL92-compatible updatable 
> views. The patch introduces new semantics into the rule system: implicit 
> and explicit rules. Implicit rules are created to implement updatable views:
> 
> _INSERT
> _NOTHING_INSERT (unconditional DO INSTEAD NOTHING rule)
> _DELETE
> _NOTHING_DELETE (unconditional DO INSTEAD NOTHING rule)
> _UPDATE
> _NOTHING_UPDATE (unconditional DO INSTEAD NOTHING rule)
> 
> These rules are marked 'implicit' in pg_rewrite, the rewriter is teached to 
> handle them different, depending on wether they are created with a rule 
> condition (a view's CHECK OPTION) or not. The CHECK OPTION itself is 
> implemented with a new system function and a conditional rule that 
> evaluates the view's WHERE condition (pg_view_update_error()).
> 
> The supported syntax is
> 
> CREATE VIEW foo AS SELECT ... [WITH [LOCAL | CASCADED] CHECK OPTION];
> 
> The LOCAL and CASCADED keywords are optional when a CHECK OPTION is 
> specified, the default is CASCADED (this syntax creates a shift/reduce 
> conflict in the grammar file i don't know how to fix).
> 
> If a user wants his own rules with CREATE RULE to be created, the implicit 
> rule gets dropped, depending what action the user selects.
> 
> The patch introduces support for pg_dump as well.
> 
> Please note that the patch isn't complete yet, but it seems it's necessary 
> to discuss its implementation on -hackers now.
> 
>         Bernd

[ Attachment, skipping... ]

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--  Bruce Momjian   http://candle.pha.pa.us EnterpriseDB    http://www.enterprisedb.com
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