cloud-fan commented on a change in pull request #28840: URL: https://github.com/apache/spark/pull/28840#discussion_r453643288
########## File path: docs/sql-ref-syntax-aux-cache-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; Review comment: nit: `db1.func1`? `tempDB` sounds like Spark supports temporary database, while it doesn't. ########## File path: sql/catalyst/src/main/scala/org/apache/spark/sql/connector/catalog/LookupCatalog.scala ########## @@ -155,4 +155,31 @@ private[sql] trait LookupCatalog extends Logging { None } } + + // TODO: move function related v2 statements to the new framework. Review comment: @imback82 do you have time to work on this TODO? ########## File path: sql/core/src/main/scala/org/apache/spark/sql/execution/command/functions.scala ########## @@ -236,6 +236,45 @@ case class ShowFunctionsCommand( } } + +/** + * A command for users to refresh the persistent function. + * The syntax of using this command in SQL is: + * {{{ + * REFRESH FUNCTION functionName + * }}} + */ +case class RefreshFunctionCommand( + databaseName: Option[String], + functionName: String) + extends RunnableCommand { + + override def run(sparkSession: SparkSession): Seq[Row] = { + val catalog = sparkSession.sessionState.catalog + if (FunctionRegistry.builtin.functionExists(FunctionIdentifier(functionName))) { + throw new AnalysisException(s"Cannot refresh builtin function $functionName") + } + if (catalog.isTemporaryFunction(FunctionIdentifier(functionName, databaseName))) { + throw new AnalysisException(s"Cannot refresh temporary function $functionName") + } + + val identifier = FunctionIdentifier( + functionName, Some(databaseName.getOrElse(catalog.getCurrentDatabase))) + // we only refresh the permanent function. + // 1. clear cached function. + // 2. register function if exists. + catalog.unregisterFunction(identifier, true) + if (catalog.isPersistentFunction(identifier)) { + val func = catalog.getFunctionMetadata(identifier) + catalog.registerFunction(func, true) Review comment: Does `registerFunction` overwrite existing entry? If it does then we don't need to add `unregisterFunction` API. ########## File path: sql/core/src/main/scala/org/apache/spark/sql/execution/command/functions.scala ########## @@ -236,6 +236,45 @@ case class ShowFunctionsCommand( } } + +/** + * A command for users to refresh the persistent function. + * The syntax of using this command in SQL is: + * {{{ + * REFRESH FUNCTION functionName + * }}} + */ +case class RefreshFunctionCommand( + databaseName: Option[String], + functionName: String) + extends RunnableCommand { + + override def run(sparkSession: SparkSession): Seq[Row] = { + val catalog = sparkSession.sessionState.catalog + if (FunctionRegistry.builtin.functionExists(FunctionIdentifier(functionName))) { + throw new AnalysisException(s"Cannot refresh builtin function $functionName") + } + if (catalog.isTemporaryFunction(FunctionIdentifier(functionName, databaseName))) { + throw new AnalysisException(s"Cannot refresh temporary function $functionName") + } + + val identifier = FunctionIdentifier( + functionName, Some(databaseName.getOrElse(catalog.getCurrentDatabase))) + // we only refresh the permanent function. + // 1. clear cached function. + // 2. register function if exists. + catalog.unregisterFunction(identifier, true) Review comment: shall we move this into the `if (catalog.isPersistentFunction(identifier))` branch? ---------------------------------------------------------------- This is an automated message from the Apache Git Service. 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