Implement a lighter format for wikipedia importance tables

lib-sql/functions/importance.sql

@@ -20,6 +20,54 @@ CREATE TYPE place_importance as (
   wikipedia TEXT
 );
 
+{% if 'wikimedia_importance' in db.tables %}
+
+CREATE OR REPLACE FUNCTION get_wikipedia_match(extratags HSTORE, country_code varchar(2))
+  RETURNS wikipedia_article_match
+  AS $$
+DECLARE
+  i INT;
+  wiki_article_title TEXT;
+  wiki_article_language TEXT;
+  result wikipedia_article_match;
+  entry RECORD;
+BEGIN
+  IF extratags ? 'wikipedia' and strpos(extratags->'wikipedia', ':') IN (3,4) THEN
+    wiki_article_language := lower(trim(split_part(extratags->'wikipedia', ':', 1)));
+    wiki_article_title := trim(substr(extratags->'wikipedia',
+                                      strpos(extratags->'wikipedia', ':') + 1));
+
+    FOR result IN
+      SELECT language, title, importance FROM wikimedia_importance
+        WHERE language = wiki_article_language
+              and title = replace(wiki_article_title, ' ', '_')
+    LOOP
+      RETURN result;
+    END LOOP;
+  END IF;
+
+  FOREACH wiki_article_language IN ARRAY ARRAY['ar','bg','ca','cs','da','de','en','es','eo','eu','fa','fr','ko','hi','hr','id','it','he','lt','hu','ms','nl','ja','no','pl','pt','kk','ro','ru','sk','sl','sr','fi','sv','tr','uk','vi','vo','war','zh']
+  LOOP
+    IF extratags ? ('wikipedia:' || wiki_article_language) THEN
+        wiki_article_title := extratags->('wikipedia:' || wiki_article_language);
+
+        FOR result IN
+          SELECT language, title, importance FROM wikimedia_importance
+            WHERE language = wiki_article_language
+                  and title = replace(wiki_article_title, ' ', '_')
+        LOOP
+          RETURN result;
+        END LOOP;
+    END IF;
+
+  END LOOP;
+
+  RETURN NULL;
+END;
+$$
+LANGUAGE plpgsql IMMUTABLE;
+
+{% else %}
 
 -- See: http://stackoverflow.com/questions/6410088/how-can-i-mimic-the-php-urldecode-function-in-postgresql
 CREATE OR REPLACE FUNCTION decode_url_part(p varchar)
@@ -93,6 +141,7 @@ END;
 $$
 LANGUAGE plpgsql STABLE;
 
+{% endif %}
 
 CREATE OR REPLACE FUNCTION compute_importance(extratags HSTORE,
                                               country_code varchar(2),
@@ -118,9 +167,16 @@ BEGIN
 
   -- Nothing? Then try with the wikidata tag.
   IF result.importance is null AND extratags ? 'wikidata' THEN
-    FOR match IN SELECT * FROM wikipedia_article
-                  WHERE wd_page_title = extratags->'wikidata'
-                  ORDER BY language = 'en' DESC, langcount DESC LIMIT 1
+    FOR match IN
+{% if 'wikimedia_importance' in db.tables %}
+      SELECT * FROM wikimedia_importance
+        WHERE wikidata = extratags->'wikidata'
+        LIMIT 1
+{% else %}
+      SELECT * FROM wikipedia_article
+        WHERE wd_page_title = extratags->'wikidata'
+        ORDER BY language = 'en' DESC, langcount DESC LIMIT 1
+{% endif %}
     LOOP
       result.importance := match.importance;
       result.wikipedia := match.language || ':' || match.title;

lib-sql/tables.sql

@@ -273,28 +273,15 @@ GRANT SELECT ON import_polygon_delete TO "{{config.DATABASE_WEBUSER}}";
 DROP SEQUENCE IF EXISTS file;
 CREATE SEQUENCE file start 1;
 
--- null table so it won't error
--- deliberately no drop - importing the table is expensive and static, if it is already there better to avoid removing it
-CREATE TABLE IF NOT EXISTS wikipedia_article (
-    language text NOT NULL,
-    title text NOT NULL,
-    langcount integer,
-    othercount integer,
-    totalcount integer,
-    lat double precision,
-    lon double precision,
-    importance double precision,
-    osm_type character(1),
-    osm_id bigint,
-    wd_page_title text,
-    instance_of text
-);
-
-CREATE TABLE IF NOT EXISTS wikipedia_redirect (
-    language text,
-    from_title text,
-    to_title text
-);
+{% if 'wikimedia_importance' not in db.tables and 'wikipedia_article' not in db.tables %}
+-- create dummy tables here, if nothing was imported
+CREATE TABLE wikimedia_importance (
+  language TEXT NOT NULL,
+  title TEXT NOT NULL,
+  importance double precision NOT NULL,
+  wikidata TEXT
+)  {{db.tablespace.address_data}};
+{% endif %}
 
 -- osm2pgsql does not create indexes on the middle tables for Nominatim
 -- Add one for lookup of associated street relations.

nominatim/clicmd/refresh.py

@@ -89,6 +89,7 @@ def run(self, args: NominatimArgs) -> int: #pylint: disable=too-many-branches, t
         from ..tools import refresh, postcodes
         from ..indexer.indexer import Indexer
 
+        need_function_refresh = args.functions
 
         if args.postcodes:
             if postcodes.can_compute(args.config.get_libpq_dsn()):
@@ -131,13 +132,7 @@ def run(self, args: NominatimArgs) -> int: #pylint: disable=too-many-branches, t
                                                 args.project_dir) > 0:
                 LOG.fatal('FATAL: Cannot update secondary importance raster data')
                 return 1
-
-        if args.functions:
-            LOG.warning('Create functions')
-            with connect(args.config.get_libpq_dsn()) as conn:
-                refresh.create_functions(conn, args.config,
-                                         args.diffs, args.enable_debug_statements)
-                self._get_tokenizer(args.config).update_sql_functions(args.config)
+            need_function_refresh = True
 
         if args.wiki_data:
             data_path = Path(args.config.WIKIPEDIA_DATA_PATH
@@ -147,8 +142,16 @@ def run(self, args: NominatimArgs) -> int: #pylint: disable=too-many-branches, t
                                                  data_path) > 0:
                 LOG.fatal('FATAL: Wikipedia importance file not found in %s', data_path)
                 return 1
+            need_function_refresh = True
+
+        if need_function_refresh:
+            LOG.warning('Create functions')
+            with connect(args.config.get_libpq_dsn()) as conn:
+                refresh.create_functions(conn, args.config,
+                                         args.diffs, args.enable_debug_statements)
+                self._get_tokenizer(args.config).update_sql_functions(args.config)
 
-        # Attention: importance MUST come after wiki data import.
+        # Attention: importance MUST come after wiki data import and after functions.
         if args.importance:
             LOG.warning('Update importance values for database')
             with connect(args.config.get_libpq_dsn()) as conn:

nominatim/db/utils.py

@@ -92,6 +92,11 @@ def __enter__(self) -> 'CopyBuffer':
         return self
 
 
+    def size(self) -> int:
+        """ Return the number of bytes the buffer currently contains.
+        """
+        return self.buffer.tell()
+
     def __exit__(self, exc_type: Any, exc_value: Any, traceback: Any) -> None:
         if self.buffer is not None:
             self.buffer.close()
@@ -115,7 +120,10 @@ def add(self, *data: Any) -> None:
 
     def copy_out(self, cur: Cursor, table: str, columns: Optional[Iterable[str]] = None) -> None:
         """ Copy all collected data into the given table.
+
+            The buffer is empty and reusable after this operation.
         """
         if self.buffer.tell() > 0:
             self.buffer.seek(0)
             cur.copy_from(self.buffer, table, columns=columns)
+            self.buffer = io.StringIO()

nominatim/tools/check_database.py

@@ -248,7 +248,10 @@ def check_existance_wikipedia(conn: Connection, _: Configuration) -> CheckResult
         return CheckState.NOT_APPLICABLE
 
     with conn.cursor() as cur:
-        cnt = cur.scalar('SELECT count(*) FROM wikipedia_article')
+        if conn.table_exists('wikimedia_importance'):
+            cnt = cur.scalar('SELECT count(*) FROM wikimedia_importance')
+        else:
+            cnt = cur.scalar('SELECT count(*) FROM wikipedia_article')
 
         return CheckState.WARN if cnt == 0 else CheckState.OK
 

nominatim/tools/refresh.py

@@ -8,6 +8,8 @@
 Functions for bringing auxiliary data in the database up-to-date.
 """
 from typing import MutableSequence, Tuple, Any, Type, Mapping, Sequence, List, cast
+import csv
+import gzip
 import logging
 from textwrap import dedent
 from pathlib import Path
@@ -16,7 +18,7 @@
 
 from nominatim.config import Configuration
 from nominatim.db.connection import Connection, connect
-from nominatim.db.utils import execute_file
+from nominatim.db.utils import execute_file, CopyBuffer
 from nominatim.db.sql_preprocessor import SQLPreprocessor
 from nominatim.version import NOMINATIM_VERSION
 
@@ -132,21 +134,89 @@ def import_wikipedia_articles(dsn: str, data_path: Path, ignore_errors: bool = F
         Returns 0 if all was well and 1 if the importance file could not
         be found. Throws an exception if there was an error reading the file.
     """
-    datafile = data_path / 'wikimedia-importance.sql.gz'
+    if import_importance_csv(dsn, data_path / 'wikimedia-importance.csv.gz') == 0 \
+       or import_importance_sql(dsn, data_path / 'wikimedia-importance.sql.gz',
+                                ignore_errors) == 0:
+        return 0
 
-    if not datafile.exists():
+    return 1
+
+
+def import_importance_csv(dsn: str, data_file: Path) -> int:
+    """ Replace wikipedia importance table with data from a
+        single CSV file.
+
+        The file must be a gzipped CSV and have the following columns:
+        language, title, importance, wikidata_id
+
+        Other columns may be present but will be ignored.
+    """
+    if not data_file.exists():
+        return 1
+
+    # Only import the first occurance of a wikidata ID.
+    # This keeps indexes and table small.
+    wd_done = set()
+
+    with connect(dsn) as conn:
+        with conn.cursor() as cur:
+            cur.drop_table('wikipedia_article')
+            cur.drop_table('wikipedia_redirect')
+            cur.drop_table('wikimedia_importance')
+            cur.execute("""CREATE TABLE wikimedia_importance (
+                             language TEXT NOT NULL,
+                             title TEXT NOT NULL,
+                             importance double precision NOT NULL,
+                             wikidata TEXT
+                           ) """)
+
+        with gzip.open(str(data_file), 'rt') as fd, CopyBuffer() as buf:
+            for row in csv.DictReader(fd, delimiter='\t', quotechar='|'):
+                wd_id = int(row['wikidata_id'][1:])
+                buf.add(row['language'], row['title'], row['importance'],
+                        None if wd_id in wd_done else row['wikidata_id'])
+                wd_done.add(wd_id)
+
+                if buf.size() > 10000000:
+                    with conn.cursor() as cur:
+                        buf.copy_out(cur, 'wikimedia_importance',
+                                     columns=['language', 'title', 'importance',
+                                              'wikidata'])
+
+            with conn.cursor() as cur:
+                buf.copy_out(cur, 'wikimedia_importance',
+                             columns=['language', 'title', 'importance', 'wikidata'])
+
+        with conn.cursor() as cur:
+            cur.execute("""CREATE INDEX IF NOT EXISTS idx_wikimedia_importance_title
+                           ON wikimedia_importance (title)""")
+            cur.execute("""CREATE INDEX IF NOT EXISTS idx_wikimedia_importance_wikidata
+                           ON wikimedia_importance (wikidata)
+                           WHERE wikidata is not null""")
+
+        conn.commit()
+
+    return 0
+
+
+def import_importance_sql(dsn: str, data_file: Path, ignore_errors: bool) -> int:
+    """ Replace wikipedia importance table with data from an SQL file.
+    """
+    if not data_file.exists():
         return 1
 
     pre_code = """BEGIN;
                   DROP TABLE IF EXISTS "wikipedia_article";
-                  DROP TABLE IF EXISTS "wikipedia_redirect"
+                  DROP TABLE IF EXISTS "wikipedia_redirect";
+                  DROP TABLE IF EXISTS "wikipedia_importance";
                """
     post_code = "COMMIT"
-    execute_file(dsn, datafile, ignore_errors=ignore_errors,
+    execute_file(dsn, data_file, ignore_errors=ignore_errors,
                  pre_code=pre_code, post_code=post_code)
 
     return 0
 
+
 def import_secondary_importance(dsn: str, data_path: Path, ignore_errors: bool = False) -> int:
     """ Replaces the secondary importance raster data table with new data.
 

test/python/cli/test_cmd_refresh.py

@@ -28,6 +28,7 @@ def setup_cli_call(self, cli_call, temp_db, cli_tokenizer_mock):
                              ('website', 'setup_website'),
                              ])
     def test_refresh_command(self, mock_func_factory, command, func):
+        mock_func_factory(nominatim.tools.refresh, 'create_functions')
         func_mock = mock_func_factory(nominatim.tools.refresh, func)
 
         assert self.call_nominatim('refresh', '--' + command) == 0
@@ -71,6 +72,7 @@ def test_refresh_wikidata_file_not_found(self, monkeypatch):
 
         assert self.call_nominatim('refresh', '--wiki-data') == 1
 
+
     def test_refresh_secondary_importance_file_not_found(self):
         assert self.call_nominatim('refresh', '--secondary-importance') == 1
 
@@ -84,16 +86,18 @@ def test_refresh_secondary_importance_new_table(self, mock_func_factory):
         assert mocks[1].called == 1
 
 
-    def test_refresh_importance_computed_after_wiki_import(self, monkeypatch):
+    def test_refresh_importance_computed_after_wiki_import(self, monkeypatch, mock_func_factory):
         calls = []
         monkeypatch.setattr(nominatim.tools.refresh, 'import_wikipedia_articles',
                             lambda *args, **kwargs: calls.append('import') or 0)
         monkeypatch.setattr(nominatim.tools.refresh, 'recompute_importance',
                             lambda *args, **kwargs: calls.append('update'))
+        func_mock = mock_func_factory(nominatim.tools.refresh, 'create_functions')
 
         assert self.call_nominatim('refresh', '--importance', '--wiki-data') == 0
 
         assert calls == ['import', 'update']
+        assert func_mock.called == 1
 
     @pytest.mark.parametrize('params', [('--data-object', 'w234'),
                                         ('--data-object', 'N23', '--data-object', 'N24'),

test/python/mocks.py

@@ -54,16 +54,17 @@ class text,
 
     def add(self, osm_type='N', osm_id=None, cls='amenity', typ='cafe', names=None,
             admin_level=None, address=None, extratags=None, geom='POINT(10 4)',
-            country=None, housenumber=None):
+            country=None, housenumber=None, rank_search=30):
         with self.conn.cursor() as cur:
             psycopg2.extras.register_hstore(cur)
             cur.execute("""INSERT INTO placex (place_id, osm_type, osm_id, class,
                                                type, name, admin_level, address,
-                                               housenumber,
+                                               housenumber, rank_search,
                                                extratags, geometry, country_code)
-                            VALUES(nextval('seq_place'), %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s)""",
+                            VALUES(nextval('seq_place'), %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s)""",
                         (osm_type, osm_id or next(self.idseq), cls, typ, names,
-                         admin_level, address, housenumber, extratags, 'SRID=4326;' + geom,
+                         admin_level, address, housenumber, rank_search,
+                         extratags, 'SRID=4326;' + geom,
                          country))
         self.conn.commit()
 

test/python/tools/test_refresh.py

@@ -35,8 +35,7 @@ def test_refresh_import_secondary_importance_testdb(dsn, src_dir, temp_db_conn,
 @pytest.mark.parametrize("replace", (True, False))
 def test_refresh_import_wikipedia(dsn, src_dir, table_factory, temp_db_cursor, replace):
     if replace:
-        table_factory('wikipedia_article')
-        table_factory('wikipedia_redirect')
+        table_factory('wikimedia_importance')
 
     # use the small wikipedia file for the API testdb
     assert refresh.import_wikipedia_articles(dsn, src_dir / 'test' / 'testdb') == 0