diff --git a/docs/source/python/recipe/flight_sql.rst b/docs/source/python/recipe/flight_sql.rst index c3bffb1331..cef2ccecb9 100644 --- a/docs/source/python/recipe/flight_sql.rst +++ b/docs/source/python/recipe/flight_sql.rst @@ -56,3 +56,8 @@ Set timeouts and other options ------------------------------ .. recipe:: flightsql_sqlite_options.py + +Set the max gRPC message size +----------------------------- + +.. recipe:: flightsql_sqlite_max_msg_size.py diff --git a/docs/source/python/recipe/flightsql_sqlite_max_msg_size.py b/docs/source/python/recipe/flightsql_sqlite_max_msg_size.py new file mode 100644 index 0000000000..1a77460d56 --- /dev/null +++ b/docs/source/python/recipe/flightsql_sqlite_max_msg_size.py @@ -0,0 +1,74 @@ +# Licensed to the Apache Software Foundation (ASF) under one +# or more contributor license agreements. See the NOTICE file +# distributed with this work for additional information +# regarding copyright ownership. The ASF licenses this file +# to you under the Apache License, Version 2.0 (the +# "License"); you may not use this file except in compliance +# with the License. You may obtain a copy of the License at +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, +# software distributed under the License is distributed on an +# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY +# KIND, either express or implied. See the License for the +# specific language governing permissions and limitations +# under the License. + +# RECIPE STARTS HERE + +#: By default, the Flight SQL driver limits the size of incoming/outgoing +#: messages. You might see an error like this if those limits are exceeded:: +#: +#: INTERNAL: [FlightSQL] grpc: received message larger than max +#: +#: These limits can be adjusted to avoid this. + +import os + +import adbc_driver_flightsql.dbapi +from adbc_driver_flightsql import DatabaseOptions + +uri = os.environ["ADBC_SQLITE_FLIGHTSQL_URI"] + +#: This query generates about 16 MiB per batch, which will trip the default +#: limit. + +query = """ +WITH RECURSIVE generate_series(value) AS ( + SELECT 1 + UNION ALL + SELECT value + 1 FROM generate_series + WHERE value + 1 <= 2048 +) +SELECT printf('%.*c', 16384, 'x') FROM generate_series +""" + +#: When we execute the query, we'll get an error. + +conn = adbc_driver_flightsql.dbapi.connect(uri) +with conn.cursor() as cur: + cur.execute(query) + + try: + cur.fetchallarrow() + except adbc_driver_flightsql.dbapi.InternalError: + # This exception is expected. + pass + else: + assert False, "Did not raise expected exception" + +conn.close() + +#: We can instead change the limit when connecting. + +conn = adbc_driver_flightsql.dbapi.connect( + uri, + db_kwargs={DatabaseOptions.WITH_MAX_MSG_SIZE.value: "2147483647"}, +) +with conn.cursor() as cur: + cur.execute(query) + + assert len(cur.fetchallarrow()) == 2048 + +conn.close()