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
