these low cardinality bits are everywhere

posthog/session_recordings/sql/session_replay_event_sql.py

@@ -109,7 +109,8 @@
     engine=kafka_engine(topic=KAFKA_CLICKHOUSE_SESSION_REPLAY_EVENTS),
 )
 
-SESSION_REPLAY_EVENTS_TABLE_MV_SQL = lambda: """
+SESSION_REPLAY_EVENTS_TABLE_MV_SQL = (
+    lambda: """
 CREATE MATERIALIZED VIEW IF NOT EXISTS session_replay_events_mv ON CLUSTER '{cluster}'
 TO {database}.{target_table} {explictly_specify_columns}
 AS SELECT
@@ -144,13 +145,13 @@
 FROM {database}.kafka_session_replay_events
 group by session_id, team_id
 """.format(
-    target_table="writable_session_replay_events",
-    cluster=settings.CLICKHOUSE_CLUSTER,
-    database=settings.CLICKHOUSE_DATABASE,
-    # ClickHouse is incorrectly expanding the type of the snapshot source column
-    # Despite it being a LowCardinality(Nullable(String)) in writable_session_replay_events
-    # The column expansion picks only Nullable(String) and so we can't select it
-    explictly_specify_columns="""(
+        target_table="writable_session_replay_events",
+        cluster=settings.CLICKHOUSE_CLUSTER,
+        database=settings.CLICKHOUSE_DATABASE,
+        # ClickHouse is incorrectly expanding the type of the snapshot source column
+        # Despite it being a LowCardinality(Nullable(String)) in writable_session_replay_events
+        # The column expansion picks only Nullable(String) and so we can't select it
+        explictly_specify_columns="""(
 `session_id` String, `team_id` Int64, `distinct_id` String,
 `min_first_timestamp` DateTime64(6, 'UTC'),
 `max_last_timestamp` DateTime64(6, 'UTC'),
@@ -160,9 +161,10 @@
 `console_log_count` Int64, `console_warn_count` Int64,
 `console_error_count` Int64, `size` Int64, `message_count` Int64,
 `event_count` Int64,
-`snapshot_source` AggregateFunction(argMin, LowCardinality(Nullable(String)), DateTime64(6, 'UTC')),
+`snapshot_source` AggregateFunction(argMin, Nullable(String), DateTime64(6, 'UTC')),
 `_timestamp` Nullable(DateTime)
 )""",
+    )
 )
 
 # Distributed engine tables are only created if CLICKHOUSE_REPLICATED