ctargett commented on a change in pull request #549: WIP:SOLR-13129 URL: https://github.com/apache/lucene-solr/pull/549#discussion_r254323572
########## File path: solr/solr-ref-guide/src/nested-documents.adoc ########## @@ -0,0 +1,321 @@ += Nested Child Documents +// 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. + +Solr supports indexing nested documents such as a blog post parent document and comments as child documents -- or products as parent documents and sizes, colors, or other variations as child documents. +The parent with all children is referred to as a "block" and it explains some of the nomenclature of related features. +At query time, the <<other-parsers.adoc#block-join-query-parsers,Block Join Query Parsers>> can search these relationships, + and the `<<transforming-result-documents.adoc#child-childdoctransformerfactory,[child]>>` Document Transformer can attach child documents to the result documents. +In terms of performance, indexing the relationships between documents usually yields much faster queries than an equivalent "query time join", + since the relationships are already stored in the index and do not need to be computed. +However, nested documents are less flexible than query time joins as it imposes rules that some applications may not be able to accept. + +.Note Review comment: Don't need to title your note with "Note" - the icon says that already. We should only add titles when they add something for the reader, we shouldn't add them just for their own sake. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on 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 With regards, Apache Git Services --------------------------------------------------------------------- To unsubscribe, e-mail: dev-unsubscr...@lucene.apache.org For additional commands, e-mail: dev-h...@lucene.apache.org
