woodbri at swoodbridge.com
Sat Nov 30 11:46:47 PST 2013
On 11/30/2013 2:18 PM, Stephen Mather wrote:
> Is pgr_createTopology deterministic in how it numbers nodes in a built
What do you mean by this?
If you build a topology on the same edge table twice, do we guarantee
that the nodes numbers will be identical?
I think the answer is NO, on line:303 of
src/common/sql/pgrouting_topology.sql there is no "order by" clause.
This would need to be added to make it deterministic because relational
set theory does not guarantee order of records in a query without
explicitly including and "order by" clause.
Write a bug if you think this is needed and state why.
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