Add a special index that contains the place nodes buffered by their
respective area according to their search rank. This replaces the
maximum area search for place nodes and reduces drastically the number
of place nodes that need to be retrieved.
This makes Nominatim compatible with osm2pgsql's default update
modus operandi of deleting and reinserting data. Deletes are diverted
into a TODO table instead of executing them. When data is reinserted,
the corresponding entry in the TODO table is deleted. After updates are
finished, the remaining entries in the TODO table are executed, doing
the same work as the delete trigger did before.
The new behaviour also works against the gazetteer output with its
insert-only mechanism.
Adds partial indexes for all geometry queries used during import.
A full index is not necessary anymore at that point. Still create
the index afterwards for use in queries.
Also adds documentation for all indexes on where they are used.
The index over geometry_sectors are mainly used for ordering
the places which need indexing. That means they function effectively
as a TODO list. Consolodate them so that they always only contain
the places which are still to do. Also add the appropriate index
for the boundary indexing phase.
Use the same update mechanism as for updates on the interpolations
themselves. Updates must solely happen in place_insert as this is
the place where actual changes of the data happen.
Instead of normalising the names simply compare them in lower
case. This removes the dependency on the tokenizer for
linking boundaries and nodes. When looking up the linked places
by place type also allow that one name is simply contained in the
other. This catches the frequent case where one of the names has
an addendum (e.g. Newport vs. City of Newport).
Drops the special index for the name lookup and insted relies
on a slightly extended version of the geometry index used for
reverse lookup. Saves around 100MB on a planet.
On Postgresql versions 11+ add an index to speed up the lookup
of housenumbers for terms found in search_name. This is really
just a band-aid around the query planer's interpretation of the
query.
Also switches to jinja-based preprocessing, which allows to
simplify the SQL files. Use 'if not exists' where possible
so that the step can be rerun to fix missing indexes.
