rdblue commented on code in PR #16961: URL: https://github.com/apache/iceberg/pull/16961#discussion_r4128030393
########## format/index-spec.md: ########## @@ -0,0 +1,731 @@ +--- +title: "Index Spec" +--- +<!-- + - 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. + --> +# Iceberg Index Specification + +## Background and Motivation + +An index is most valuable when it is a property of the table rather than of the engine that built it. This +specification defines a common format for index metadata and a common storage architecture for index data, so that any +engine can build an index, maintain it, and use it to plan queries against the table. + +## Goals + +* **Portability** -- An index written by one engine will be readable by any other engine. +* **Separation** -- Index metadata will be committed separately from table metadata. Building and maintaining an index + will not rewrite the table. +* **Optionality** -- Indexes will be optional. Engines may ignore an index they do not support. +* **Consistency** -- Each index snapshot will index exactly the live rows of one source table snapshot. Review Comment: This falls more into overview / approach. There is a specific consistency model we are going for, but we aren't aiming for "consistency" -- it isn't clear what that would mean. The description here outlines what that means, but this isn't a goal, bit is a part of the design. -- 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]
