Re: DROP COLUMN

Rod Taylor wrote:
> On Mon, 2002-07-15 at 11:30, Christopher Kings-Lynne wrote:
> > OK, more DROP COLUMN funny business:
> >
> > Assuming that selects, updates and deletes all ignore the dropped column,
> > what happens with things like alter table statements?
> >
> > You can still quite happily set the default for a dropped column, etc.
> >
> > Will I have to add a dropped column check in everywhere that a command is
> > able to target a column. ie. create index, cluster, alter table, etc,
> > etc.? Or is there an easier way?
>
> Each utility statement does some kind of a SearchSysCache() to determine
> the status of the column (whether it exists or not).
>
> You may want to write a wrapper function in lsyscache.c that returns the
> status of the column (dropped or not). Perhaps the att tuple could be
> fetched through this function (processed on the way out) -- though
> lsyscache routines tend to return simple items.

Excellent idea. That's how temp tables worked, by bypassing the
syscache. I wonder if you could just prevent dropped columns from being
returned by the syscache. That may work just fine.

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