jduo commented on a change in pull request #12573: URL: https://github.com/apache/arrow/pull/12573#discussion_r820232922
########## File path: docs/source/format/FlightSql.rst ########## @@ -0,0 +1,159 @@ +.. 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. + +.. _flight-sql: + +================ +Arrow Flight SQL +================ + +Arrow Flight SQL is a protocol for interacting with SQL databases +using the Arrow in-memory format and the :doc:`Flight RPC +<./Flight>` framework. + +Generally, a database will implement the RPC methods according to the +specification, but does not need to implement a client-side driver. A +database client can use the provided Flight SQL client to interact +with any database that supports the necessary endpoints. + +.. warning:: Flight SQL is **experimental** and changes to the + protocol may still be made. + +RPC Methods +=========== + +Flight SQL reuses the predefined RPC methods in Arrow Flight, and +provides various commands that pair those methods with request/response +messages defined via Protobuf (see below). + +SQL Metadata +------------ + +Flight SQL provides a variety of commands to fetch metadata about the +database server. + +All of these commands can be used with the GetFlightInfo and GetSchema +RPC methods. The Protobuf request message should be packed into a +google.protobuf.Any message, then serialized and packed as the ``cmd`` +field in a CMD-type FlightDescriptor. + +If the command is used with GetFlightInfo, the server will return a +FlightInfo response. The client should then use the Ticket(s) in the +FlightInfo with the DoGet RPC method to fetch a Arrow data containing +the results of the command. In other words, metadata is returned as +Arrow data, just like query results themselves. + +The schema returned by GetSchema or DoGet for a particular command is +fixed according to the specification. + +``CommandGetCatalogs`` + List the catalogs available in the database. The definition varies + by vendor. + +``CommandGetCrossReference`` + List the foreign key columns in a given table that reference + columns in a given parent table. + +``CommandGetDbSchemas`` + List the schemas (note: *not* an Arrow schema) available in the Review comment: ```suggestion List the schemas (note: a grouping of tables, *not* an Arrow schema) available in the ``` -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
