docs: add migration for search_name_* tables

diff --git a/docs/admin/Migration.md b/docs/admin/Migration.md
index 66b4c28b41046134058c0ada04424367e8336e5e..9b6395e6a3e278ca1a31c6f582f8d4d7bb564c5d 100644 (file)
--- a/docs/admin/Migration.md
+++ b/docs/admin/Migration.md
@@ -8,6 +8,18 @@ SQL statements should be executed from the PostgreSQL commandline. Execute
 
 ## 3.5.0 -> master
 
+### Change of layout of search_name_* tables
+
+The table need a different index for nearest place lookup. Recreate the
+indexs suing the following shell script:
+
+```bash
+for table in `psql -d nominatim -c "SELECT tablename FROM pg_tables WHERE tablename LIKE 'search_name_%'" -tA | grep -v search_name_blank`;
+do
+    psql -d nominatim -c "DROP INDEX idx_${table}_centroid_place; CREATE INDEX idx_${table}_centroid_place ON ${table} USING gist (centroid) WHERE ((address_rank >= 2) AND (address_rank <= 25)); DROP INDEX idx_${table}_centroid_street; CREATE INDEX idx_${table}_centroid_street ON ${table} USING gist (centroid) WHERE ((address_rank >= 26) AND (address_rank <= 27))";
+done
+```
+
 ### Removal of html output
 
 The debugging UI is no longer directly provided with Nominatim. Instead we