[postgis-users] topology cleaning up

[Bo Guo]

strk,

- If I drop the topology, the topology built on "other" jurisdictions in 
the same street network layer will be gone.  My intention is only to 
update the topology of the jurisdiction whose street network has been 
changed.

- I will give removing constraints a try and report the result.


On Wed, Jan 09, 2019 at 07:59:45AM -0700, Bo Guo wrote:

> Hi there,
>
> My street table has road segment geometries from several jurisdictions.  The
> business rule requires me to build topology not for the entire table, but on
> a jurisdiction-by-jurisdiction basis.  I will need to re-generate the
> topology when geometry updates happen.
>
> I can rebuild new topology, but that leaves old topology in the topo tables.
> So I want to remove the old topology before building new topology using
> topology.totopogeom for a jurisdiction. However, the constraints in and
> among the topology tables prevented me from the delete operation.

How about using DropTopology to start with a fresh one ?

> Since the topology is only managed by the postgis' topology engine, can I
> just remove some of the constraints?  This will not only allow deletion and
> but improve some operations as well?

Removing constraints would likely improve some operations, but I'm not
clear which constraints are preventing you from creating a whole new
topology as your business rule seems to require.

--strk;

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