Re: per-tablespace random_page_cost/seq_page_cost

On Nov 1, 2009, at 7:43 AM, Greg Stark <gsstark@mit.edu> wrote:

> On Sat, Oct 31, 2009 at 6:04 PM, Robert Haas <robertmhaas@gmail.com>  
> wrote:
>> Looking at this a little more, it seems that part of the motivation
>> for the existing design is that user-created AMs might require
>> arbitrary options, which therefore can't be wired into the system
>> catalogs.  There's no equivalent for tablespaces (we could add one
>> some day, I suppose), so there's less intrinsic reason to think we
>> have to do it that way.
>
> Can't custom modules define arbitrary options which they declare can
> be defined per tablespace?

Yeah, probably we can support that for free, although I'm not sure  
there is much demand for it.

> We could have a column for all booleans, a column for all integers,
> etc. but that's not really any more normalized than having a single
> - how to marshal each value
> type.

That has no advantages and several disadvantages AFAICS.

I don't want to get sidetracked here. The real issue is the one I  
discussed in the portion of the email you didn't quote...

...Robert