Get rid of sqlite3.Row and adjust SQL queries

docs/changes/newsfragments/4446.improved

@@ -1,3 +1,3 @@
 Improve performance of ``sqlite3`` converters and adapters used to write and read in the database.
 
-Get rid of irrelevant unpacking from ``sqlite3.Row`` to ``list``.
+Get rid of ``sqlite3.Row`` and irrelevant unpacking to ``list``.

qcodes/dataset/data_set.py

@@ -1174,11 +1174,14 @@ def unsubscribe_all(self) -> None:
         """
         Remove all subscribers
         """
-        sql = "select * from sqlite_master where type = 'trigger';"
+        sql = """
+        SELECT name FROM sqlite_master
+        WHERE type = 'trigger'
+        """
         triggers = atomic_transaction(self.conn, sql).fetchall()
         with atomic(self.conn) as conn:
-            for trigger in triggers:
-                remove_trigger(conn, trigger['name'])
+            for (trigger,) in triggers:
+                remove_trigger(conn, trigger)
             for sub in self.subscribers.values():
                 sub.schedule_stop()
                 sub.join()

qcodes/dataset/experiment_container.py

@@ -169,8 +169,10 @@ def data_set(self, counter: int) -> DataSet:
 
     def data_sets(self) -> list[DataSetProtocol]:
         """Get all the datasets of this experiment"""
-        runs = get_runs(self.conn, self.exp_id)
-        return [load_by_id(run['run_id'], conn=self.conn) for run in runs]
+        return [
+            load_by_id(run_id, conn=self.conn)
+            for run_id in get_runs(self.conn, self.exp_id)
+        ]
 
     def last_data_set(self) -> DataSetProtocol:
         """Get the last dataset of this experiment"""
@@ -216,8 +218,7 @@ def experiments(conn: ConnectionPlus | None = None) -> list[Experiment]:
     """
     conn = conn_from_dbpath_or_conn(conn=conn, path_to_db=None)
     log.info(f"loading experiments from {conn.path_to_dbfile}")
-    rows = get_experiments(conn)
-    return [load_experiment(row['exp_id'], conn) for row in rows]
+    return [load_experiment(exp_id, conn) for exp_id in get_experiments(conn)]
 
 
 def new_experiment(

qcodes/dataset/sqlite/database.py

@@ -149,9 +149,6 @@ def connect(name: str | Path, debug: bool = False, version: int = -1) -> Connect
                            f"version of QCoDeS supports up to "
                            f"version {latest_supported_version}")
 
-    # sqlite3 options
-    conn.row_factory = sqlite3.Row
-
     # Make sure numpy ints and floats types are inserted properly
     for numpy_int in numpy_ints:
         sqlite3.register_adapter(numpy_int, int)

qcodes/dataset/sqlite/db_upgrades/upgrade_2_to_3.py

@@ -16,7 +16,7 @@
     atomic_transaction,
     transaction,
 )
-from qcodes.dataset.sqlite.query_helpers import one
+from qcodes.dataset.sqlite.query_helpers import get_description_map, one
 
 log = logging.getLogger(__name__)
 
@@ -29,8 +29,8 @@ def _2to3_get_result_tables(conn: ConnectionPlus) -> dict[int, str]:
     data = cur.fetchall()
     cur.close()
     results = {}
-    for row in data:
-        results[row['run_id']] = row['result_table_name']
+    for run_id, result_table_name in data:
+        results[run_id] = result_table_name
     return results
 
 
@@ -47,9 +47,7 @@ def _2to3_get_layout_ids(conn: ConnectionPlus) -> DefaultDict[int, list[int]]:
 
     results: DefaultDict[int, list[int]] = defaultdict(list)
 
-    for row in data:
-        run_id = row['run_id']
-        layout_id = row['layout_id']
+    for run_id, layout_id in data:
         results[run_id].append(layout_id)
 
     return results
@@ -68,9 +66,7 @@ def _2to3_get_indeps(conn: ConnectionPlus) -> DefaultDict[int, list[int]]:
     cur.close()
     results: DefaultDict[int, list[int]] = defaultdict(list)
 
-    for row in data:
-        run_id = row['run_id']
-        layout_id = row['layout_id']
+    for run_id, layout_id in data:
         results[run_id].append(layout_id)
 
     return results
@@ -89,9 +85,7 @@ def _2to3_get_deps(conn: ConnectionPlus) -> DefaultDict[int, list[int]]:
     cur.close()
     results: DefaultDict[int, list[int]] = defaultdict(list)
 
-    for row in data:
-        run_id = row['run_id']
-        layout_id = row['layout_id']
+    for run_id, layout_id in data:
         results[run_id].append(layout_id)
 
     return results
@@ -112,9 +106,7 @@ def _2to3_get_dependencies(conn: ConnectionPlus) -> DefaultDict[int, list[int]]:
     if len(data) == 0:
         return results
 
-    for row in data:
-        dep = row['dependent']
-        indep = row['independent']
+    for dep, indep in data:
         results[dep].append(indep)
 
     return results
@@ -129,11 +121,8 @@ def _2to3_get_layouts(conn: ConnectionPlus) -> dict[int, tuple[str, str, str, st
     cur.execute(query)
 
     results: dict[int, tuple[str, str, str, str]] = {}
-    for row in cur.fetchall():
-        results[row['layout_id']] = (row['parameter'],
-                                     row['label'],
-                                     row['unit'],
-                                     row['inferred_from'])
+    for layout_id, parameter, label, unit, inferred_from in cur.fetchall():
+        results[layout_id] = (parameter, label, unit, inferred_from)
     return results
 
 
@@ -159,10 +148,11 @@ def _2to3_get_paramspecs(
         # get the data type
         sql = f'PRAGMA TABLE_INFO("{result_table_name}")'
         c = transaction(conn, sql)
+        description = get_description_map(c)
         paramtype = None
         for row in c.fetchall():
-            if row['name'] == name:
-                paramtype = row['type']
+            if row[description["name"]] == name:
+                paramtype = row[description["type"]]
                 break
         if paramtype is None:
             raise TypeError(f"Could not determine type of {name} during the"