[postgis-devel] Caching Double-based Boxes

[Sandro Santilli]

On Fri, Nov 25, 2011 at 08:11:06AM +0100, Nicklas Avén wrote:
> I don't know if "my" issue has any practical impact. But just so I
> understand. 
> 
> I have never thought about if before, but from this discussion I
> understand that the boxes is stored in two places. Both the index and
> together with the geometry. Am I right?

Yes, you're right.

> Just some very naive thoughts. 
> We have no access to the index bbox to use in the functions? 

Not in a straightforward way, no.

> There is nothing that points to the index key from the geometry? Is it
> so. It is the same reason we can't get the extent from a table from the
> index?

I'd think you could, altought not easily.

But the main reason why you don't want to do that is that you don't
want to be _forced_ to have an index in order to process values.
Note that Geometry values could also be literal, never touching a table.

--strk;

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