findepi commented on code in PR #13706: URL: https://github.com/apache/datafusion/pull/13706#discussion_r1877863653
########## docs/source/user-guide/sql/dialect.md: ########## @@ -0,0 +1,38 @@ +<!--- + 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. +--> + +# SQL Dialect + +By default, Apache DataFusion follows the [PostgreSQL SQL dialect]. +For Array/List functions and semantics, it follows the [DuckDB SQL dialect]. + +[duckdb sql dialect]: https://duckdb.org/docs/sql/functions/array +[postgresql sql dialect]: https://www.postgresql.org/docs/current/sql.html + +## Rationale + +SQL Engines have a choice to either use an existing SQL dialect or define their +own. Using an existing dialect may not fit perfectly as it is hard to match +semantics exactly (need bug-for-bug compatibility), and is likely not what all +users want. However, it avoids the (very significant) effort of defining +semantics as well as documenting and teaching users about them. + +As Apache DataFusion is highly customizable, systems built on DataFusion can and do +update functions and SQL syntax to model other systems, such as Apache Spark or Review Comment: and type rules ########## docs/source/user-guide/sql/dialect.md: ########## @@ -0,0 +1,38 @@ +<!--- + 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. +--> + +# SQL Dialect + +By default, Apache DataFusion follows the [PostgreSQL SQL dialect]. Review Comment: When reading something that includes "by default", a reader may have natural question "how do i change this?" Should we have a tip how to amend the behavior if the default doesn't please the user? -- 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: github-unsubscr...@datafusion.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: github-unsubscr...@datafusion.apache.org For additional commands, e-mail: github-h...@datafusion.apache.org
