Re: Table modification

[Dave Page]

> -----Original Message-----
> From: Jean-Michel POURE [mailto:[EMAIL PROTECTED]] 
> Sent: 02 October 2001 10:41
> To: [EMAIL PROTECTED]
> Subject: Re: [pgadmin-hackers] Table modification
> 
> 
> 
> >This is the correct way to do it, though I appreciate your 
> problem with 
> >large tables. Perhaps (for Table objects only) we should have a 
> >Tables.DeferRebuild property. When set true, all rebuilds 
> triggered by 
> >mods of individual properties or collections will get queued 
> up until 
> >an update method is fired. That way, the update method can 
> reduce all 
> >the required rebuilds that are queued up into as small an 
> operation as 
> >possible.
> >
> >What do you think?
> Agreed. Another question: how do we enable table reorganization (i.e. 
> change the order of columns)?

Ug. Don't know. I suppose that's a special case (like table/column rename)
where you can't do it any way other than with a special method.

> > > Do I miss something?
> >I don't think so. I would suggest that we both sleep on how 
> to achieve 
> >the above for a while - in the meantime look at the more simple mods 
> >like updating functions/views/triggers.
> Agreed. What are your plans as regards 
> functions/views/triggers? 
>
Currently I'm working on Revision Control/PostgreSQL 7.2 related updates. I
think it would be fairly easy to implement function/view/trigger
modification *without* project rebuilding. This should be the fisrt step I
think (if someone manually edits such an object they'll still have the same
dependency problems anyway, so they're no worse off!).

> Do you confirm creating objects in 
> their OID order should work for solving 
> dependencies?

As I said, that's how pg_dump does it afaict. The only case where it (and
pg_dump) fails that I've found so far is illustrated with:

1) Create table with a text column.
2) Create a function that returns a string with no arguments required.
3) Alter the column default to use that function.

The table reload will fail because the function has a higher oid and
therefore is not yet created. pg_dump isn't clever enough to create and
alter later.

Interestingly, if the function is dependant on the table you can create a
cirular dependency.... I don't know how we'd fix that, though I suspect it
might involve Revision Control.

Regards, Dave.