Merge pull request #3530 from lonvia/clean-use-of-os-environ

[nominatim.git] / docs / admin / Maintenance.md

diff --git a/docs/admin/Maintenance.md b/docs/admin/Maintenance.md
index 782b377cceb6c30584d6d8ca3b5a86074fe04d52..325e6f8f22410f3d1c96ccb8b5ea7d1cb26a1ca0 100644 (file)
--- a/docs/admin/Maintenance.md
+++ b/docs/admin/Maintenance.md
@@ -34,18 +34,39 @@ to rerun the statistics computation when adding larger amounts of new data,
 for example, when adding an additional country via `nominatim add-data`.
 
 
+## Forcing recomputation of places and areas
+
+Command: `nominatim refresh --data-object [NWR]<id> --data-area [NWR]<id>`
+
+When running replication updates, Nominatim tries to recompute the search
+and address information for all places that are affected by a change. But it
+needs to restrict the total number of changes to make sure it can keep up
+with the minutely updates. Therefore it will refrain from propagating changes
+that affect a lot of objects.
+
+The administrator may force an update of places in the database.
+`nominatim refresh --data-object` invalidates a single OSM object.
+`nominatim refresh --data-area` invalidates an OSM object and all dependent
+objects. That are usually the places that inside its area or around the
+center of the object. Both commands expect the OSM object as an argument
+of the form OSM type + OSM id. The type must be `N` (node), `W` (way) or
+`R` (relation).
+
+After invalidating the object, indexing must be run again. If continuous
+update are running in the background, the objects will be recomputed together
+with the next round of updates. Otherwise you need to run `nominatim index`
+to finish the recomputation.
+
+
 ## Removing large deleted objects
 
+Command: `nominatim admin --clean-deleted <PostgreSQL Time Interval>`
+
 Nominatim refuses to delete very large areas because often these deletions are
 accidental and are reverted within hours. Instead the deletions are logged in
 the `import_polygon_delete` table and left to the administrator to clean up.
 
-There is currently no command to do that. You can use the following SQL
-query to force a deletion on all objects that have been deleted more than
-a certain timespan ago (here: 1 month):
+To run this command you will need to pass a PostgreSQL time interval. For example to 
+delete any objects that have been deleted more than a month ago you would run:
+`nominatim admin --clean-deleted '1 month'`
 
-```sql
-SELECT place_force_delete(p.place_id) FROM import_polygon_delete d, placex p
-WHERE p.osm_type = d.osm_type and p.osm_id = d.osm_id
-      and age(p.indexed_date) > '1 month'::interval
-```