JingsongLi commented on code in PR #5028: URL: https://github.com/apache/paimon/pull/5028#discussion_r1948078431
########## paimon-common/src/main/java/org/apache/paimon/fileindex/bitmap/BitmapFileIndexMetaV2.java: ########## @@ -0,0 +1,415 @@ +/* + * 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.paimon.fileindex.bitmap; + +import org.apache.paimon.data.BinaryString; +import org.apache.paimon.fs.SeekableInputStream; +import org.apache.paimon.options.MemorySize; +import org.apache.paimon.options.Options; +import org.apache.paimon.types.DataType; + +import java.io.BufferedInputStream; +import java.io.DataInput; +import java.io.DataInputStream; +import java.io.DataOutput; +import java.io.InputStream; +import java.util.ArrayList; +import java.util.Collections; +import java.util.Comparator; +import java.util.HashMap; +import java.util.LinkedHashMap; +import java.util.LinkedList; +import java.util.List; +import java.util.Map; +import java.util.function.Function; + +/** + * When the bitmap-indexed column cardinality is high, using the first version of the bitmap index + * format will take a lot of time to read the entire dictionary. But in fact we don't need a full + * dictionary when dealing with a small number of predicates, the performance of predicate hits on + * the bitmap can be improved by creating a secondary index on the dictionary. + * + * <pre> + * Bitmap file index format (V2) + * +-------------------------------------------------+----------------- + * ｜ version (1 byte) = 2 ｜ + * +-------------------------------------------------+ + * ｜ row count (4 bytes int) ｜ + * +-------------------------------------------------+ + * ｜ non-null value bitmap number (4 bytes int) ｜ + * +-------------------------------------------------+ + * ｜ has null value (1 byte) ｜ + * +-------------------------------------------------+ + * ｜ null value offset (4 bytes if has null value) ｜ HEAD + * +-------------------------------------------------+ + * ｜ null bitmap length (4 bytes if has null value) ｜ + * +-------------------------------------------------+ + * ｜ bitmap index block number (4 bytes int) ｜ + * +-------------------------------------------------+ + * ｜ value 1 | offset 1 ｜ + * +-------------------------------------------------+ + * ｜ value 2 | offset 2 ｜ + * +-------------------------------------------------+ + * ｜ ... ｜ + * +-------------------------------------------------+ + * ｜ bitmap blocks offset (4 bytes int) ｜ + * +-------------------------------------------------+----------------- + * ｜ bitmap index block 1 ｜ + * +-------------------------------------------------+ + * ｜ bitmap index block 2 ｜ INDEX BLOCKS + * +-------------------------------------------------+ + * ｜ ... ｜ + * +-------------------------------------------------+----------------- + * ｜ serialized bitmap 1 ｜ + * +-------------------------------------------------+ + * ｜ serialized bitmap 2 ｜ + * +-------------------------------------------------+ BITMAP BLOCKS + * ｜ serialized bitmap 3 ｜ + * +-------------------------------------------------+ + * ｜ ... ｜ + * +-------------------------------------------------+----------------- + * + * index block format: Review Comment: Maybe we should have ability to compress index block? -- 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]
