[postgis-devel] automatic BVOL on spatial columns

[Paul Ramsey]

I am loath to load more functionality in AddGeometryColumn, because I 
really really want to make it go away in the long term. I think it's a 
bit of nastiness.

How about a somewhat larger hammer? How about having bboxes for 
anything that is not a point and that has more than 4 vertices? or 8? 
something like that? Just a single rule, some compile-time defines for 
the bold, and leave it there?

P.

On 23-Dec-04, at 6:03 AM, strk at refractions.net wrote:

> The bounding box of an LWGEOM geometry is
> an optional 'cache', currently absent at
> construction time.
>
> Bounding boxes can be added using addBBOX(geom)
> and removed using dropBBOX(geom).
>
> Having a bbox cached speeds up bbox operation
> like &&, but increases on-disk size.
>
> Note that an index scan does not need to
> compute the bbox, but its construction does.
> Also note that our GiST index has a RECHECK
> clause on each operator, thus practically
> needing the bbox check (so it's computation)
> for every 'candidate' row returned from the
> index scan.
>
> Previous (HWGEOM) geometry type did *always*
> have this cache available.
>
> My proposal is to add a RULE on INSERT and
> UPDATES of geometry columns from within
> AddGeoemtryColumn, so that all geometry
> columns exept 'POINT' type (for which bbox
> computation is very fast) have a BBOX
> computed.
>
> What do you think ?
>
> --strk;
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