[ 
https://issues.apache.org/jira/browse/PARQUET-1950?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17248906#comment-17248906
 ] 

ASF GitHub Bot commented on PARQUET-1950:
-----------------------------------------

gszadovszky commented on a change in pull request #164:
URL: https://github.com/apache/parquet-format/pull/164#discussion_r542300290



##########
File path: CoreFeatures.md
##########
@@ -0,0 +1,181 @@
+<!--
+  - 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.
+  -->
+
+# Parquet Core Features
+
+This document lists the core features for each parquet-format release. This
+list is a subset of the features which parquet-format makes available.
+
+## Purpose
+
+The list of core features for a certian release makes a compliance level that
+the different implementations can tied to. If an implementation claims that it
+provides the functionality of a parquet-format release core features it must
+implement all of the listed features according the specification (both read and

Review comment:
       Good point, I'll do that.




----------------------------------------------------------------
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.

For queries about this service, please contact Infrastructure at:
us...@infra.apache.org


> Define core features / compliance level
> ---------------------------------------
>
>                 Key: PARQUET-1950
>                 URL: https://issues.apache.org/jira/browse/PARQUET-1950
>             Project: Parquet
>          Issue Type: New Feature
>          Components: parquet-format
>            Reporter: Gabor Szadovszky
>            Assignee: Gabor Szadovszky
>            Priority: Major
>
> Parquet format is getting more and more features while the different 
> implementations cannot keep the pace and left behind with some features 
> implemented and some are not. In many cases it is also not clear if the 
> related feature is mature enough to be used widely or more an experimental 
> one.
> These are huge issues that makes hard ensure interoperability between the 
> different implementations.
> The following idea came up in a 
> [discussion|https://lists.apache.org/thread.html/rde5cba8443487bccd47593ddf5dfb39f69c729d260165cb936a1a289%40%3Cdev.parquet.apache.org%3E].
>  Create a now document in the parquet-format repository that lists the "core 
> features". This document is versioned by the parquet-format releases. This 
> way a certain version of "core features" defines a level of compatibility 
> between the different implementations. This version number can be written to 
> a new field (e.g. complianceLevel) in the footer. If an implementation writes 
> a file with a version in the field it must implement all the related "core 
> features" (read and write) and must not use any other features at write 
> because it makes the data unreadable by another implementation if only the 
> same level of "core features" are implemented.
> For example if we have encoding A listed in the version 1 "core features" but 
> encoding B is not then at "complianceLevel = 1" we can use encoding A but we 
> cannot use encoding B because it would make the related data unreadable.



--
This message was sent by Atlassian Jira
(v8.3.4#803005)

Reply via email to