cloud-fan commented on a change in pull request #34291: URL: https://github.com/apache/spark/pull/34291#discussion_r729836712
########## File path: sql/catalyst/src/main/java/org/apache/spark/sql/connector/read/SupportsPushDownLimit.java ########## @@ -0,0 +1,42 @@ +/* + * 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. + */ + +package org.apache.spark.sql.connector.read; + +import org.apache.spark.annotation.Evolving; +import org.apache.spark.sql.connector.expressions.Limit; + +/** + * A mix-in interface for {@link Scan}. Data sources can implement this interface to + * push down LIMIT to the data source. + * + * @since 3.3.0 + */ +@Evolving +public interface SupportsPushDownLimit extends Scan { + + /** + * Pushes down Limit to the data source. Returns true if Limit can be pushed down, + * false otherwise. + */ + boolean pushLimit(Limit limit); Review comment: It seems can simply be `void pushLimit(int limit);` ########## File path: sql/catalyst/src/main/java/org/apache/spark/sql/connector/read/SupportsPushDownLimit.java ########## @@ -0,0 +1,42 @@ +/* + * 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. + */ + +package org.apache.spark.sql.connector.read; + +import org.apache.spark.annotation.Evolving; +import org.apache.spark.sql.connector.expressions.Limit; + +/** + * A mix-in interface for {@link Scan}. Data sources can implement this interface to + * push down LIMIT to the data source. + * + * @since 3.3.0 + */ +@Evolving +public interface SupportsPushDownLimit extends Scan { + + /** + * Pushes down Limit to the data source. Returns true if Limit can be pushed down, + * false otherwise. + */ + boolean pushLimit(Limit limit); Review comment: We don't need any return value, because Spark doesn't care and will still run LIMIT anyway. ########## File path: sql/core/src/main/scala/org/apache/spark/sql/execution/datasources/v2/V2ScanRelationPushDown.scala ########## @@ -225,6 +226,35 @@ object V2ScanRelationPushDown extends Rule[LogicalPlan] with PredicateHelper { withProjection } + def applyLimit(plan: LogicalPlan): LogicalPlan = plan.transform { + case globalLimit @ GlobalLimit(_, child) => child match { Review comment: We can use `Limit(...)` to match a pair of global and local limit -- 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] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
