Topology: Support security access to tables

[aperi2007]

Actually an user could access directly to the tables and a wrongly query could destroy the topology. As esample an user could think to execute this query:

delete * from edge_data where left_face=right_face to remove dangles edges.

But this query could destroy the topology because don't update the node table.

Instead the right query is this:

delete ST_RemEdgeModFace(idedge) from edge_data where left_face=right_face;

this correctly update also the node table.

To avoid this , a good choice should be deny the access (write/update/delete) directly to the tables using and allow the access directly only to a user with a "topology_master" specific grant. And leave to all the user only the "read" grant to the tables.

[robe]

Milestone renamed