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Re: BUG #3403: ver 8.2 can't add serial column to temp table,but 8.1 can

From: Heikki Linnakangas <heikki(at)enterprisedb(dot)com>
To: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
Cc: Zdenek Kotala <Zdenek(dot)Kotala(at)Sun(dot)COM>, Jasen Betts <jasen(at)treshna(dot)com>, pgsql-bugs(at)postgresql(dot)org
Subject: Re: BUG #3403: ver 8.2 can't add serial column to temp table,but 8.1 can
Date: 2007-06-22 19:40:55
Message-ID: 467C25C7.4000500@enterprisedb.com (view raw or flat)
Thread:
Lists: pgsql-bugs
Tom Lane wrote:
> This is actually a bit nasty.  Your proposed patch doesn't really work,
> because of the concern that is now commented at the head of
> transformAlterTableStmt:
> 
>  * CAUTION: resist the temptation to do any work here that depends on the
>  * current state of the table.  Actual execution of the command might not
>  * occur till some future transaction.  Hence, we do only purely syntactic
>  * transformations here, comparable to the processing of CREATE TABLE.
> 
> IOW, we don't actually *know* at parse analysis time which table will be
> affected.

I don't understand that. Why would the execution be delayed to a future 
transaction? You can't PREPARE an ALTER TABLE, right?

According to the comments in transformInhRelation, it has the same 
problem...

> Maybe we should give up doing any CREATE/ALTER processing at all at
> parse analysis time, and push it all to execution time.  I got rid of
> parse-time processing of other utility statements during the plan
> caching work a couple months ago, because of concerns very much like
> this, but I hadn't bit the bullet for CREATE/ALTER TABLE because it was
> such a huge chunk of code.  But maybe we'd better do it.

We'll still need something smaller to back patch, I think. :(

-- 
   Heikki Linnakangas
   EnterpriseDB   http://www.enterprisedb.com

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Subject: Re: BUG #3403: ver 8.2 can't add serial column to temp table,but 8.1 can
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