flyrain commented on code in PR #7105: URL: https://github.com/apache/iceberg/pull/7105#discussion_r1317695173
########## format/partition-statistics-spec.md: ########## @@ -0,0 +1,43 @@ +--- +title: "Partition Statistics Spec" +url: partition-statistics-spec +toc: true +disableSidebar: true +--- +<!-- + - 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. + --> + +# Partition Statistics file format + +This is a specification for partition statistics files. It is designed to store statistics information +for every partition value as a row in the **table default format** sorted based on the `partition`. + +The schema of the file is as follows: + +| Field Id | Field Name | Field Type | isOptional | Doc | +|----------|------------------------------|--------------|------------|-----------------------------------------------------------------------------------------------------------------------------| +| 1 | partition | StructType | false | See [PartitionData](https://github.com/apache/iceberg/blob/master/core/src/main/java/org/apache/iceberg/PartitionData.java) | +| 2 | spec_id | IntegerType | false | Partition spec id | +| 3 | data_record_count | LongType | false | Count of records in data files | +| 4 | data_file_count | IntegerType | false | Count of data files | +| 5 | position_delete_record_count | LongType | true | Count of records in position delete files | +| 6 | position_delete_file_count | IntegerType | true | Count of position delete files | +| 7 | equality_delete_record_count | LongType | true | Count of records in equality delete files | +| 8 | equality_delete_file_count | IntegerType | true | Count of equality delete files | Review Comment: > Writers that produce positional deletes would be able to produce this count directly during writes. This may not be true. For example, for a data file `df1`, we could have two positional delete files(`pdf1`, `pdf2`) applying to it. `pdf1` and `pdf2` may delete the same row in `df1`. The writer may not know if a row has been deleted previously. Not 100% sure though. Needs inputs from @szehon-ho @aokolnychyi -- 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]
