Merge pull request #898 from koordinates/journal_mode

Use journal_mode = WAL on annotations.db

CHANGELOG.md

@@ -10,6 +10,7 @@ _When adding new entries to the changelog, please include issue/PR numbers where
 - Better protection against XSS in the HTML diff viewer. [#884](https://github.com/koordinates/kart/pull/884)
 - Speed-up: greatly reduces the time taken to update the index file after checking out LFS tiles to the working copy. [#880](https://github.com/koordinates/kart/pull/880)
 - Adds `--with-dataset-types` option to `kart data ls` command (and deprecates `kart data version`). [#892](https://github.com/koordinates/kart/issues/892)
+- Use `journal_mode = WAL` in annotations.db sqlite database. [#898](https://github.com/koordinates/kart/pull/898)
 
 ## 0.14.0
 

kart/annotations/db.py

@@ -57,7 +57,7 @@ def ignore_readonly_db(session):
 
 @contextlib.contextmanager
 def _annotations_session(db_path):
-    engine = sqlite_engine(db_path)
+    engine = sqlite_engine(db_path, journal_mode="WAL")
     sm = sessionmaker(bind=engine)
     inspector = sqlalchemy.inspect(engine)
     is_readonly = None

kart/sqlalchemy/gpkg.py

@@ -17,13 +17,15 @@ class Db_GPKG(BaseDb):
     preparer = SQLiteIdentifierPreparer(SQLiteDialect())
 
     @classmethod
-    def create_engine(cls, path, **kwargs):
+    def create_engine(cls, path, *, journal_mode=None, **kwargs):
         def _on_connect(pysqlite_conn, connection_record):
             pysqlite_conn.isolation_level = None
             pysqlite_conn.enable_load_extension(True)
             pysqlite_conn.load_extension(spatialite_path)
             pysqlite_conn.enable_load_extension(False)
             dbcur = pysqlite_conn.cursor()
+            if journal_mode:
+                dbcur.execute(f"PRAGMA journal_mode = {journal_mode};")
             dbcur.execute("SELECT EnableGpkgMode();")
             dbcur.execute("PRAGMA foreign_keys = ON;")
             dbcur.execute(f"PRAGMA cache_size = -{cls.GPKG_CACHE_SIZE_MiB * 1024};")
@@ -64,7 +66,7 @@ def list_tables(cls, sess, db_schema=None):
 
     @classmethod
     def pk_name(cls, sess, db_schema=None, table=None):
-        """ Find the primary key for a GeoPackage table """
+        """Find the primary key for a GeoPackage table"""
 
         # Requirement 150:
         # A feature table or view SHALL have a column that uniquely identifies the

kart/sqlalchemy/sqlite.py

@@ -5,14 +5,16 @@
 import sqlalchemy
 
 
-def sqlite_engine(path):
+def sqlite_engine(path, *, journal_mode=None):
     """
     An engine for non-spatial, non-GPKG sqlite databases.
     """
 
     def _on_connect(pysqlite_conn, connection_record):
         pysqlite_conn.isolation_level = None
         dbcur = pysqlite_conn.cursor()
+        if journal_mode:
+            dbcur.execute(f"PRAGMA journal_mode = {journal_mode};")
         dbcur.execute("PRAGMA foreign_keys = ON;")
 
     path = os.path.expanduser(path)