Enhance exposures views

[ricardogsilva]

This PR is connected to #15

It enhances the ingestexposures management command in order to support:

• Initial parsing of each exposure asset's taxonomy into normalized categories. The current implementation can only parse the GEM Building Taxonomy. In the future we will need to add support for other taxonomies that are featured on the sample data. Implementation is done as a PL/pgSQL function. The current version in not very performant (generating ~40 views takes about 40 minutes on my desktop). In the future we hope to optimize it.

  The parsed taxonomy is put on each view's hev_e_taxonomy column. Parsing the taxonomy entails mapping from the source taxonomy (e.g. GEM Building Taxonomy) to a set of previously defined categories. The mapped taxonomic categories are encoded with the following pattern:

  <category1-name:<category1-value#<category2-name><category2-value>

  For example:

  material:masonry#occupancy:residential#construction_date:unknown

  This mapped taxonomy column can be used to filter a layer's exposure assets according to multiple categories

• Generation of two materialized views for each exposure model:

  • coarse view: uses the exposure assets' the_geom geometry in order to provide a coarse representation
  • detail view: uses the exposure assets' full_geom (when available, if not it falls back to using the the_geom column) in order to show a more detailed representation of the asset

[ricardogsilva]

Yes, you are right. The geometry type of building layers is not correct. I must have changed it by mistake while I was refactoring the settings formats... I'll fix.

[ricardogsilva]

Fixed.

Here is a screenshot with both the coarse and detail view for exposure model 65 (osm test ph) that shows buildings, and also the coarse view of the exposure model 115 (osm tnz main roads) that shows roads.