dongjoon-hyun commented on a change in pull request #28840: URL: https://github.com/apache/spark/pull/28840#discussion_r442524344
########## File path: docs/sql-ref-syntax-aux-refresh-function.md ########## @@ -0,0 +1,60 @@ +--- +layout: global +title: REFRESH FUNCTION +displayTitle: REFRESH FUNCTION +license: | + 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. +--- + +### Description + +`REFRESH FUNCTION` statement invalidates the cached function entry, which includes a class name +and resource location of the given function. The invalidated cache is populated right away. +Note that `REFRESH FUNCTION` only works for permanent functions. Refreshing native functions or temporary functions will cause an exception. + +### Syntax + +```sql +REFRESH FUNCTION function_identifier +``` + +### Parameters + +* **function_identifier** + + Specifies a function name, which is either a qualified or unqualified name. If no database identifier is provided, uses the current database. + + **Syntax:** `[ database_name. ] function_name` + +### Examples + +```sql +-- The cached entry of the function will be refreshed +-- The function is resolved from the current database as the function name is unqualified. +REFRESH FUNCTION func1; + +-- The cached entry of the function will be refreshed +-- The function is resolved from tempDB database as the function name is qualified. +REFRESH FUNCTION tempDB.func1; +``` + +### Related Statements + +* [CACHE TABLE](sql-ref-syntax-aux-cache-cache-table.html) +* [CLEAR CACHE](sql-ref-syntax-aux-cache-clear-cache.html) +* [UNCACHE TABLE](sql-ref-syntax-aux-cache-uncache-table.html) +* [REFRESH TABLE](sql-ref-syntax-aux-refresh-table.html) Review comment: Do we need to mention the above four data-related statement? ---------------------------------------------------------------- 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. For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: reviews-unsubscr...@spark.apache.org For additional commands, e-mail: reviews-h...@spark.apache.org
