force reschedule after putting something in the query pool

src/nominatim_db/db/query_pool.py

@@ -19,7 +19,10 @@
 QueueItem = Optional[Tuple[psycopg.abc.Query, Any]]
 
 class QueryPool:
+    """ Pool to run SQL queries in parallel asynchronous execution.
 
+        The results of the queries is discarded.
+    """
     def __init__(self, dsn: str, pool_size: int = 1, **conn_args: Any) -> None:
         self.wait_time = 0.0
         self.query_queue: 'asyncio.Queue[QueueItem]' = asyncio.Queue()
@@ -29,12 +32,17 @@ def __init__(self, dsn: str, pool_size: int = 1, **conn_args: Any) -> None:
 
 
     async def put_query(self, query: psycopg.abc.Query, params: Any) -> None:
+        """ Schedule a query for execution.
+        """
         tstart = time.time()
         await self.query_queue.put((query, params))
         self.wait_time += time.time() - tstart
+        await asyncio.sleep(0)
 
 
     async def finish(self) -> None:
+        """ Wait for all queries to finish and close the pool.
+        """
         for _ in self.pool:
             await self.query_queue.put(None)
 
@@ -69,4 +77,3 @@ async def __aenter__(self) -> 'QueryPool':
 
     async def __aexit__(self, exc_type: Any, exc_value: Any, traceback: Any) -> None:
         await self.finish()
-

src/nominatim_db/indexer/indexer.py

@@ -7,13 +7,11 @@
 """
 Main work horse for indexing (computing addresses) the database.
 """
-from typing import Optional, List, cast
+from typing import cast
 import logging
 import time
-import asyncio
 
 import psycopg
-from psycopg_pool import AsyncConnectionPool
 
 from ..db.connection import connect, execute_scalar
 from ..db.query_pool import QueryPool