sunchao commented on code in PR #38904: URL: https://github.com/apache/spark/pull/38904#discussion_r1041451334
########## sql/catalyst/src/main/java/org/apache/spark/sql/connector/read/colstats/ColumnStatistics.java: ########## @@ -0,0 +1,60 @@ +/* + * 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.colstats; Review Comment: I wonder if it's better to name the package `org.apache.spark.sql.connector.read.stats` ########## sql/catalyst/src/main/java/org/apache/spark/sql/connector/read/colstats/ColumnStatistics.java: ########## @@ -0,0 +1,60 @@ +/* + * 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.colstats; + +import org.apache.spark.annotation.Evolving; +import java.math.BigInteger; +import java.util.Optional; +import java.util.OptionalLong; + +/** + * An interface to represent column statistics, which is part of + * {@link Statistics}. + * + * @since 3.4.0 + */ +@Evolving +public interface ColumnStatistics { + default Optional<BigInteger> distinctCount() { + return Optional.empty(); + } + + default Optional<Object> min() { + return Optional.empty(); + } + + default Optional<Object> max() { + return Optional.empty(); + } + + default Optional<BigInteger> nullCount() { + return Optional.empty(); + } + + default OptionalLong avgLen() { Review Comment: could we add some comments for each of these methods? since they are public APIs. ########## sql/catalyst/src/main/java/org/apache/spark/sql/connector/read/Statistics.java: ########## @@ -31,4 +35,7 @@ public interface Statistics { OptionalLong sizeInBytes(); OptionalLong numRows(); + default Optional<HashMap<NamedReference, ColumnStatistics>> columnStats() { Review Comment: why it has to be a `HashMap` in the API? can it just be `Map`? ########## sql/catalyst/src/main/java/org/apache/spark/sql/connector/read/colstats/Histogram.java: ########## @@ -0,0 +1,33 @@ +/* + * 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.colstats; + +import org.apache.spark.annotation.Evolving; + +/** + * An interface to represent an equi-height histogram, which is a part of + * {@link ColumnStatistics}. Equi-height histogram represents the distribution of + * a column's values by a sequence of bins. + * + * @since 3.4.0 + */ +@Evolving +public interface Histogram { + double height(); Review Comment: ditto: more comments. -- 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: reviews-unsubscr...@spark.apache.org 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
