writer-jill commented on code in PR #12946: URL: https://github.com/apache/druid/pull/12946#discussion_r954929494
########## docs/querying/nested-columns.md: ########## @@ -0,0 +1,546 @@ +--- +id: nested-columns +title: "Nested columns" +sidebar_label: Nested columns +--- + +<!-- + ~ 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. + ~ + ~ Nested columns is an experimental feature that is subject to + ~ change or removal at any time. + --> + +> Nested columns is an experimental feature available starting in Apache Druid 24.0. As an experimental feature, functionality documented on this page is subject to change or removal in future releases. Review the release notes and this page to stay up to date with changes. + +You can ingest and store nested JSON in an Apache Druid column as a `COMPLEX<json>` data type. Druid indexes and optimizes the nested data. This means you can use JSON functions to extract ‘literal’ values at ingestion time using the `transformSpec` or in the SELECT clause when using multi-stage query architecture. + +Druid SQL JSON functions let you extract, transform, and create `COMPLEX<json>` values. Additionally, you can use certain `JSONPath` operators to extract values from nested data structures. + +Druid currently supports ingesting JSON-format nested columns with this feature. If you want to ingest nested data in another format, consider using the [flattenSpec object](../ingestion/data-formats.md#flattenspec). Review Comment: @clintropolis what's the description to (possibly) dump? This link doesn't show me anything specific. -- 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]
