Use a nested set model to incorporate region hierarchies in queries.
author Dennis Nienhüser
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committer Dennis Nienhüser
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commit 19736b4302f6d119d1415e3480cd5889d90bf757
tree 00fcafa3a7fd57b107eca7f664faf68b83959581
parent 00db0c1f85e04e954a0353ae6d67fbcdee1df8af
Use a nested set model to incorporate region hierarchies in queries.

Administrative boundaries form a hierarchy of polygons. They're
transformed into a tree by the preprocessor and its structure is
represented by two attributes lft and rgt in the database. This avoids
subsequent queries that'd be needed when doing a tree traveseral at
query time.
src/plugins/runner/local-osm-search/OsmDatabase.cpp