<!DOCTYPE html><html lang="en"><head><meta charSet="utf-8"/><meta http-equiv="X-UA-Compatible" content="IE=edge"/><title>Multi-value dimensions · Apache Druid</title><meta name="viewport" content="width=device-width"/><link rel="canonical" href="https://druid.apache.org/docs/0.20.0/querying/multi-value-dimensions.html"/><meta name="generator" content="Docusaurus"/><meta name="description" content="&lt;!--"/><meta name="docsearch:language" content="en"/><meta name="docsearch:version" content="0.20.0" /><meta property="og:title" content="Multi-value dimensions · Apache Druid"/><meta property="og:type" content="website"/><meta property="og:url" content="https://druid.apache.org/index.html"/><meta property="og:description" content="&lt;!--"/><meta property="og:image" content="https://druid.apache.org/img/druid_nav.png"/><meta name="twitter:card" content="summary"/><meta name="twitter:image" content="https://druid.apache.org/img/druid_nav.png"/><link rel="shortcut icon" href="/img/favicon.png"/><link rel="stylesheet" href="https://cdn.jsdelivr.net/docsearch.js/1/docsearch.min.css"/><link rel="stylesheet" href="//cdnjs.cloudflare.com/ajax/libs/highlight.js/9.12.0/styles/default.min.css"/><script async="" src="https://www.googletagmanager.com/gtag/js?id=UA-131010415-1"></script><script>
              window.dataLayer = window.dataLayer || [];
              function gtag(){dataLayer.push(arguments); }
              gtag('js', new Date());
              gtag('config', 'UA-131010415-1');
            </script><link rel="stylesheet" href="https://use.fontawesome.com/releases/v5.7.2/css/all.css"/><link rel="stylesheet" href="/css/code-block-buttons.css"/><script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/clipboard.js/2.0.4/clipboard.min.js"></script><script type="text/javascript" src="/js/code-block-buttons.js"></script><script src="/js/scrollSpy.js"></script><link rel="stylesheet" href="/css/main.css"/><script src="/js/codetabs.js"></script></head><body class="sideNavVisible separateOnPageNav"><div class="fixedHeaderContainer"><div class="headerWrapper wrapper"><header><a href="/"><img class="logo" src="/img/druid_nav.png" alt="Apache Druid"/></a><div class="navigationWrapper navigationSlider"><nav class="slidingNav"><ul class="nav-site nav-site-internal"><li class=""><a href="/technology" target="_self">Technology</a></li><li class=""><a href="/use-cases" target="_self">Use Cases</a></li><li class=""><a href="/druid-powered" target="_self">Powered By</a></li><li class="siteNavGroupActive"><a href="/docs/0.20.0/design/index.html" target="_self">Docs</a></li><li class=""><a href="/community/" target="_self">Community</a></li><li class=""><a href="https://www.apache.org" target="_self">Apache</a></li><li class=""><a href="/downloads.html" target="_self">Download</a></li><li class="navSearchWrapper reactNavSearchWrapper"><input type="text" id="search_input_react" placeholder="Search" title="Search"/></li></ul></nav></div></header></div></div><div class="navPusher"><div class="docMainWrapper wrapper"><div class="docsNavContainer" id="docsNav"><nav class="toc"><div class="toggleNav"><section class="navWrapper wrapper"><div class="navBreadcrumb wrapper"><div class="navToggle" id="navToggler"><div class="hamburger-menu"><div class="line1"></div><div class="line2"></div><div class="line3"></div></div></div><h2><i>›</i><span>Concepts</span></h2><div class="tocToggler" id="tocToggler"><i class="icon-toc"></i></div></div><div class="navGroups"><div class="navGroup"><h3 class="navGroupCategoryTitle collapsible">Getting started<span class="arrow"><svg width="24" height="24" viewBox="0 0 24 24"><path fill="#565656" d="M7.41 15.41L12 10.83l4.59 4.58L18 14l-6-6-6 6z"></path><path d="M0 0h24v24H0z" fill="none"></path></svg></span></h3><ul class="hide"><li class="navListItem"><a class="navItem" href="/docs/0.20.0/design/index.html">Introduction to Apache Druid</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/tutorials/index.html">Quickstart</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/tutorials/docker.html">Docker</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/operations/single-server.html">Single server deployment</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/tutorials/cluster.html">Clustered deployment</a></li></ul></div><div class="navGroup"><h3 class="navGroupCategoryTitle collapsible">Tutorials<span class="arrow"><svg width="24" height="24" viewBox="0 0 24 24"><path fill="#565656" d="M7.41 15.41L12 10.83l4.59 4.58L18 14l-6-6-6 6z"></path><path d="M0 0h24v24H0z" fill="none"></path></svg></span></h3><ul class="hide"><li class="navListItem"><a class="navItem" href="/docs/0.20.0/tutorials/tutorial-batch.html">Loading files natively</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/tutorials/tutorial-kafka.html">Load from Apache Kafka</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/tutorials/tutorial-batch-hadoop.html">Load from Apache Hadoop</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/tutorials/tutorial-query.html">Querying data</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/tutorials/tutorial-rollup.html">Roll-up</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/tutorials/tutorial-retention.html">Configuring data retention</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/tutorials/tutorial-update-data.html">Updating existing data</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/tutorials/tutorial-compaction.html">Compacting segments</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/tutorials/tutorial-delete-data.html">Deleting data</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/tutorials/tutorial-ingestion-spec.html">Writing an ingestion spec</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/tutorials/tutorial-transform-spec.html">Transforming input data</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/tutorials/tutorial-kerberos-hadoop.html">Kerberized HDFS deep storage</a></li></ul></div><div class="navGroup"><h3 class="navGroupCategoryTitle collapsible">Design<span class="arrow"><svg width="24" height="24" viewBox="0 0 24 24"><path fill="#565656" d="M7.41 15.41L12 10.83l4.59 4.58L18 14l-6-6-6 6z"></path><path d="M0 0h24v24H0z" fill="none"></path></svg></span></h3><ul class="hide"><li class="navListItem"><a class="navItem" href="/docs/0.20.0/design/architecture.html">Design</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/design/segments.html">Segments</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/design/processes.html">Processes and servers</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/dependencies/deep-storage.html">Deep storage</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/dependencies/metadata-storage.html">Metadata storage</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/dependencies/zookeeper.html">ZooKeeper</a></li></ul></div><div class="navGroup"><h3 class="navGroupCategoryTitle collapsible">Ingestion<span class="arrow"><svg width="24" height="24" viewBox="0 0 24 24"><path fill="#565656" d="M7.41 15.41L12 10.83l4.59 4.58L18 14l-6-6-6 6z"></path><path d="M0 0h24v24H0z" fill="none"></path></svg></span></h3><ul class="hide"><li class="navListItem"><a class="navItem" href="/docs/0.20.0/ingestion/index.html">Ingestion</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/ingestion/data-formats.html">Data formats</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/ingestion/schema-design.html">Schema design tips</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/ingestion/data-management.html">Data management</a></li><div class="navGroup subNavGroup"><h4 class="navGroupSubcategoryTitle">Stream ingestion</h4><ul><li class="navListItem"><a class="navItem" href="/docs/0.20.0/development/extensions-core/kafka-ingestion.html">Apache Kafka</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/development/extensions-core/kinesis-ingestion.html">Amazon Kinesis</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/ingestion/tranquility.html">Tranquility</a></li></ul></div><div class="navGroup subNavGroup"><h4 class="navGroupSubcategoryTitle">Batch ingestion</h4><ul><li class="navListItem"><a class="navItem" href="/docs/0.20.0/ingestion/native-batch.html">Native batch</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/ingestion/hadoop.html">Hadoop-based</a></li></ul></div><li class="navListItem"><a class="navItem" href="/docs/0.20.0/ingestion/tasks.html">Task reference</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/ingestion/faq.html">Troubleshooting FAQ</a></li></ul></div><div class="navGroup"><h3 class="navGroupCategoryTitle collapsible">Querying<span class="arrow"><svg width="24" height="24" viewBox="0 0 24 24"><path fill="#565656" d="M7.41 15.41L12 10.83l4.59 4.58L18 14l-6-6-6 6z"></path><path d="M0 0h24v24H0z" fill="none"></path></svg></span></h3><ul class="hide"><li class="navListItem"><a class="navItem" href="/docs/0.20.0/querying/sql.html">Druid SQL</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/querying/querying.html">Native queries</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/querying/query-execution.html">Query execution</a></li><div class="navGroup subNavGroup"><h4 class="navGroupSubcategoryTitle">Concepts</h4><ul><li class="navListItem"><a class="navItem" href="/docs/0.20.0/querying/datasource.html">Datasources</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/querying/joins.html">Joins</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/querying/lookups.html">Lookups</a></li><li class="navListItem navListItemActive"><a class="navItem" href="/docs/0.20.0/querying/multi-value-dimensions.html">Multi-value dimensions</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/querying/multitenancy.html">Multitenancy</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/querying/caching.html">Query caching</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/querying/query-context.html">Context parameters</a></li></ul></div><div class="navGroup subNavGroup"><h4 class="navGroupSubcategoryTitle">Native query types</h4><ul><li class="navListItem"><a class="navItem" href="/docs/0.20.0/querying/timeseriesquery.html">Timeseries</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/querying/topnquery.html">TopN</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/querying/groupbyquery.html">GroupBy</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/querying/scan-query.html">Scan</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/querying/searchquery.html">Search</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/querying/timeboundaryquery.html">TimeBoundary</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/querying/segmentmetadataquery.html">SegmentMetadata</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/querying/datasourcemetadataquery.html">DatasourceMetadata</a></li></ul></div><div class="navGroup subNavGroup"><h4 class="navGroupSubcategoryTitle">Native query components</h4><ul><li class="navListItem"><a class="navItem" href="/docs/0.20.0/querying/filters.html">Filters</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/querying/granularities.html">Granularities</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/querying/dimensionspecs.html">Dimensions</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/querying/aggregations.html">Aggregations</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/querying/post-aggregations.html">Post-aggregations</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/misc/math-expr.html">Expressions</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/querying/having.html">Having filters (groupBy)</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/querying/limitspec.html">Sorting and limiting (groupBy)</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/querying/topnmetricspec.html">Sorting (topN)</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/querying/sorting-orders.html">String comparators</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/querying/virtual-columns.html">Virtual columns</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/development/geo.html">Spatial filters</a></li></ul></div></ul></div><div class="navGroup"><h3 class="navGroupCategoryTitle collapsible">Configuration<span class="arrow"><svg width="24" height="24" viewBox="0 0 24 24"><path fill="#565656" d="M7.41 15.41L12 10.83l4.59 4.58L18 14l-6-6-6 6z"></path><path d="M0 0h24v24H0z" fill="none"></path></svg></span></h3><ul class="hide"><li class="navListItem"><a class="navItem" href="/docs/0.20.0/configuration/index.html">Configuration reference</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/development/extensions.html">Extensions</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/configuration/logging.html">Logging</a></li></ul></div><div class="navGroup"><h3 class="navGroupCategoryTitle collapsible">Operations<span class="arrow"><svg width="24" height="24" viewBox="0 0 24 24"><path fill="#565656" d="M7.41 15.41L12 10.83l4.59 4.58L18 14l-6-6-6 6z"></path><path d="M0 0h24v24H0z" fill="none"></path></svg></span></h3><ul class="hide"><li class="navListItem"><a class="navItem" href="/docs/0.20.0/operations/druid-console.html">Web console</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/operations/getting-started.html">Getting started with Apache Druid</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/operations/basic-cluster-tuning.html">Basic cluster tuning</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/operations/api-reference.html">API reference</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/operations/high-availability.html">High availability</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/operations/rolling-updates.html">Rolling updates</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/operations/rule-configuration.html">Retaining or automatically dropping data</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/operations/metrics.html">Metrics</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/operations/alerts.html">Alerts</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/operations/other-hadoop.html">Working with different versions of Apache Hadoop</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/operations/http-compression.html">HTTP compression</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/operations/tls-support.html">TLS support</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/operations/password-provider.html">Password providers</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/operations/dump-segment.html">dump-segment tool</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/operations/reset-cluster.html">reset-cluster tool</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/operations/insert-segment-to-db.html">insert-segment-to-db tool</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/operations/pull-deps.html">pull-deps tool</a></li><div class="navGroup subNavGroup"><h4 class="navGroupSubcategoryTitle">Misc</h4><ul><li class="navListItem"><a class="navItem" href="/docs/0.20.0/operations/management-uis.html">Legacy Management UIs</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/operations/deep-storage-migration.html">Deep storage migration</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/operations/export-metadata.html">Export Metadata Tool</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/operations/metadata-migration.html">Metadata Migration</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/operations/segment-optimization.html">Segment Size Optimization</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/operations/use_sbt_to_build_fat_jar.html">Content for build.sbt</a></li></ul></div></ul></div><div class="navGroup"><h3 class="navGroupCategoryTitle collapsible">Development<span class="arrow"><svg width="24" height="24" viewBox="0 0 24 24"><path fill="#565656" d="M7.41 15.41L12 10.83l4.59 4.58L18 14l-6-6-6 6z"></path><path d="M0 0h24v24H0z" fill="none"></path></svg></span></h3><ul class="hide"><li class="navListItem"><a class="navItem" href="/docs/0.20.0/development/overview.html">Developing on Druid</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/development/modules.html">Creating extensions</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/development/javascript.html">JavaScript functionality</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/development/build.html">Build from source</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/development/versioning.html">Versioning</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/development/experimental.html">Experimental features</a></li></ul></div><div class="navGroup"><h3 class="navGroupCategoryTitle collapsible">Misc<span class="arrow"><svg width="24" height="24" viewBox="0 0 24 24"><path fill="#565656" d="M7.41 15.41L12 10.83l4.59 4.58L18 14l-6-6-6 6z"></path><path d="M0 0h24v24H0z" fill="none"></path></svg></span></h3><ul class="hide"><li class="navListItem"><a class="navItem" href="/docs/0.20.0/misc/papers-and-talks.html">Papers</a></li></ul></div><div class="navGroup"><h3 class="navGroupCategoryTitle collapsible">Hidden<span class="arrow"><svg width="24" height="24" viewBox="0 0 24 24"><path fill="#565656" d="M7.41 15.41L12 10.83l4.59 4.58L18 14l-6-6-6 6z"></path><path d="M0 0h24v24H0z" fill="none"></path></svg></span></h3><ul class="hide"><li class="navListItem"><a class="navItem" href="/docs/0.20.0/comparisons/druid-vs-elasticsearch.html">Apache Druid vs Elasticsearch</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/comparisons/druid-vs-key-value.html">Apache Druid vs. Key/Value Stores (HBase/Cassandra/OpenTSDB)</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/comparisons/druid-vs-kudu.html">Apache Druid vs Kudu</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/comparisons/druid-vs-redshift.html">Apache Druid vs Redshift</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/comparisons/druid-vs-spark.html">Apache Druid vs Spark</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/comparisons/druid-vs-sql-on-hadoop.html">Apache Druid vs SQL-on-Hadoop</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/design/auth.html">Authentication and Authorization</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/design/broker.html">Broker</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/design/coordinator.html">Coordinator Process</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/design/historical.html">Historical Process</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/design/indexer.html">Indexer Process</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/design/indexing-service.html">Indexing Service</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/design/middlemanager.html">MiddleManager Process</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/design/overlord.html">Overlord Process</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/design/router.html">Router Process</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/design/peons.html">Peons</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/development/extensions-core/approximate-histograms.html">Approximate Histogram aggregators</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/development/extensions-core/avro.html">Apache Avro</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/development/extensions-core/azure.html">Microsoft Azure</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/development/extensions-core/bloom-filter.html">Bloom Filter</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/development/extensions-core/datasketches-extension.html">DataSketches extension</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/development/extensions-core/datasketches-hll.html">DataSketches HLL Sketch module</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/development/extensions-core/datasketches-quantiles.html">DataSketches Quantiles Sketch module</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/development/extensions-core/datasketches-theta.html">DataSketches Theta Sketch module</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/development/extensions-core/datasketches-tuple.html">DataSketches Tuple Sketch module</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/development/extensions-core/druid-basic-security.html">Basic Security</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/development/extensions-core/druid-kerberos.html">Kerberos</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/development/extensions-core/druid-lookups.html">Cached Lookup Module</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/development/extensions-core/druid-ranger-security.html">Apache Ranger Security</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/development/extensions-core/google.html">Google Cloud Storage</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/development/extensions-core/hdfs.html">HDFS</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/development/extensions-core/kafka-extraction-namespace.html">Apache Kafka Lookups</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/development/extensions-core/lookups-cached-global.html">Globally Cached Lookups</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/development/extensions-core/mysql.html">MySQL Metadata Store</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/development/extensions-core/orc.html">ORC Extension</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/development/extensions-core/druid-pac4j.html">Druid pac4j based Security extension</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/development/extensions-core/parquet.html">Apache Parquet Extension</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/development/extensions-core/postgresql.html">PostgreSQL Metadata Store</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/development/extensions-core/protobuf.html">Protobuf</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/development/extensions-core/s3.html">S3-compatible</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/development/extensions-core/simple-client-sslcontext.html">Simple SSLContext Provider Module</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/development/extensions-core/stats.html">Stats aggregator</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/development/extensions-core/test-stats.html">Test Stats Aggregators</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/development/extensions-contrib/ambari-metrics-emitter.html">Ambari Metrics Emitter</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/development/extensions-contrib/cassandra.html">Apache Cassandra</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/development/extensions-contrib/cloudfiles.html">Rackspace Cloud Files</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/development/extensions-contrib/distinctcount.html">DistinctCount Aggregator</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/development/extensions-contrib/graphite.html">Graphite Emitter</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/development/extensions-contrib/influx.html">InfluxDB Line Protocol Parser</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/development/extensions-contrib/influxdb-emitter.html">InfluxDB Emitter</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/development/extensions-contrib/kafka-emitter.html">Kafka Emitter</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/development/extensions-contrib/materialized-view.html">Materialized View</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/development/extensions-contrib/momentsketch-quantiles.html">Moment Sketches for Approximate Quantiles module</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/development/extensions-contrib/moving-average-query.html">Moving Average Query</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/development/extensions-contrib/opentsdb-emitter.html">OpenTSDB Emitter</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/development/extensions-contrib/redis-cache.html">Druid Redis Cache</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/development/extensions-contrib/sqlserver.html">Microsoft SQLServer</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/development/extensions-contrib/statsd.html">StatsD Emitter</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/development/extensions-contrib/tdigestsketch-quantiles.html">T-Digest Quantiles Sketch module</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/development/extensions-contrib/thrift.html">Thrift</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/development/extensions-contrib/time-min-max.html">Timestamp Min/Max aggregators</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/development/extensions-contrib/gce-extensions.html">GCE Extensions</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/development/extensions-contrib/aliyun-oss.html">Aliyun OSS</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/querying/hll-old.html">Cardinality/HyperUnique aggregators</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/querying/select-query.html">Select</a></li><li class="navListItem"><a class="navItem" href="/docs/0.20.0/ingestion/standalone-realtime.html">Realtime Process</a></li></ul></div></div></section></div><script>
            var coll = document.getElementsByClassName('collapsible');
            var checkActiveCategory = true;
            for (var i = 0; i < coll.length; i++) {
              var links = coll[i].nextElementSibling.getElementsByTagName('*');
              if (checkActiveCategory){
                for (var j = 0; j < links.length; j++) {
                  if (links[j].classList.contains('navListItemActive')){
                    coll[i].nextElementSibling.classList.toggle('hide');
                    coll[i].childNodes[1].classList.toggle('rotate');
                    checkActiveCategory = false;
                    break;
                  }
                }
              }

              coll[i].addEventListener('click', function() {
                var arrow = this.childNodes[1];
                arrow.classList.toggle('rotate');
                var content = this.nextElementSibling;
                content.classList.toggle('hide');
              });
            }

            document.addEventListener('DOMContentLoaded', function() {
              createToggler('#navToggler', '#docsNav', 'docsSliderActive');
              createToggler('#tocToggler', 'body', 'tocActive');

              var headings = document.querySelector('.toc-headings');
              headings && headings.addEventListener('click', function(event) {
                var el = event.target;
                while(el !== headings){
                  if (el.tagName === 'A') {
                    document.body.classList.remove('tocActive');
                    break;
                  } else{
                    el = el.parentNode;
                  }
                }
              }, false);

              function createToggler(togglerSelector, targetSelector, className) {
                var toggler = document.querySelector(togglerSelector);
                var target = document.querySelector(targetSelector);

                if (!toggler) {
                  return;
                }

                toggler.onclick = function(event) {
                  event.preventDefault();

                  target.classList.toggle(className);
                };
              }
            });
        </script></nav></div><div class="container mainContainer docsContainer"><div class="wrapper"><div class="post"><header class="postHeader"><a class="edit-page-link button" href="https://github.com/apache/druid/edit/master/docs/querying/multi-value-dimensions.md" target="_blank" rel="noreferrer noopener">Edit</a><h1 id="__docusaurus" class="postHeaderTitle">Multi-value dimensions</h1></header><article><div><span><!--
  ~ 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.
  -->
<p>Apache Druid supports &quot;multi-value&quot; string dimensions. These are generated when an input field contains an
array of values instead of a single value (e.g. JSON arrays, or a TSV field containing one or more <code>listDelimiter</code>
characters).</p>
<p>This document describes the behavior of groupBy (topN has similar behavior) queries on multi-value dimensions when they
are used as a dimension being grouped by. See the section on multi-value columns in
<a href="../design/segments.html#multi-value-columns">segments</a> for internal representation details. Examples in this document
are in the form of <a href="querying.html">native Druid queries</a>. Refer to the <a href="sql.html">Druid SQL documentation</a> for details
about using multi-value string dimensions in SQL.</p>
<h2><a class="anchor" aria-hidden="true" id="querying-multi-value-dimensions"></a><a href="#querying-multi-value-dimensions" aria-hidden="true" class="hash-link"><svg class="hash-link-icon" aria-hidden="true" height="16" version="1.1" viewBox="0 0 16 16" width="16"><path fill-rule="evenodd" d="M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z"></path></svg></a>Querying multi-value dimensions</h2>
<p>Suppose, you have a dataSource with a segment that contains the following rows, with a multi-value dimension
called <code>tags</code>.</p>
<pre><code class="hljs">{<span class="hljs-string">"timestamp"</span>: <span class="hljs-string">"2011-01-12T00:00:00.000Z"</span>, <span class="hljs-string">"tags"</span>: [<span class="hljs-string">"t1"</span>,<span class="hljs-string">"t2"</span>,<span class="hljs-string">"t3"</span>]}  <span class="hljs-meta">#row1</span>
{<span class="hljs-string">"timestamp"</span>: <span class="hljs-string">"2011-01-13T00:00:00.000Z"</span>, <span class="hljs-string">"tags"</span>: [<span class="hljs-string">"t3"</span>,<span class="hljs-string">"t4"</span>,<span class="hljs-string">"t5"</span>]}  <span class="hljs-meta">#row2</span>
{<span class="hljs-string">"timestamp"</span>: <span class="hljs-string">"2011-01-14T00:00:00.000Z"</span>, <span class="hljs-string">"tags"</span>: [<span class="hljs-string">"t5"</span>,<span class="hljs-string">"t6"</span>,<span class="hljs-string">"t7"</span>]}  <span class="hljs-meta">#row3</span>
{<span class="hljs-string">"timestamp"</span>: <span class="hljs-string">"2011-01-14T00:00:00.000Z"</span>, <span class="hljs-string">"tags"</span>: []}                <span class="hljs-meta">#row4</span>
</code></pre>
<h3><a class="anchor" aria-hidden="true" id="filtering"></a><a href="#filtering" aria-hidden="true" class="hash-link"><svg class="hash-link-icon" aria-hidden="true" height="16" version="1.1" viewBox="0 0 16 16" width="16"><path fill-rule="evenodd" d="M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z"></path></svg></a>Filtering</h3>
<p>All query types, as well as <a href="aggregations.html#filtered-aggregator">filtered aggregators</a>, can filter on multi-value
dimensions. Filters follow these rules on multi-value dimensions:</p>
<ul>
<li>Value filters (like &quot;selector&quot;, &quot;bound&quot;, and &quot;in&quot;) match a row if any of the values of a multi-value dimension match
the filter.</li>
<li>The Column Comparison filter will match a row if the dimensions have any overlap.</li>
<li>Value filters that match <code>null</code> or <code>&quot;&quot;</code> (empty string) will match empty cells in a multi-value dimension.</li>
<li>Logical expression filters behave the same way they do on single-value dimensions: &quot;and&quot; matches a row if all
underlying filters match that row; &quot;or&quot; matches a row if any underlying filters match that row; &quot;not&quot; matches a row
if the underlying filter does not match the row.</li>
</ul>
<p>For example, this &quot;or&quot; filter would match row1 and row2 of the dataset above, but not row3:</p>
<pre><code class="hljs">{
  <span class="hljs-attr">"type"</span>: <span class="hljs-string">"or"</span>,
  <span class="hljs-attr">"fields"</span>: [
    {
      <span class="hljs-attr">"type"</span>: <span class="hljs-string">"selector"</span>,
      <span class="hljs-attr">"dimension"</span>: <span class="hljs-string">"tags"</span>,
      <span class="hljs-attr">"value"</span>: <span class="hljs-string">"t1"</span>
    },
    {
      <span class="hljs-attr">"type"</span>: <span class="hljs-string">"selector"</span>,
      <span class="hljs-attr">"dimension"</span>: <span class="hljs-string">"tags"</span>,
      <span class="hljs-attr">"value"</span>: <span class="hljs-string">"t3"</span>
    }
  ]
}
</code></pre>
<p>This &quot;and&quot; filter would match only row1 of the dataset above:</p>
<pre><code class="hljs">{
  <span class="hljs-attr">"type"</span>: <span class="hljs-string">"and"</span>,
  <span class="hljs-attr">"fields"</span>: [
    {
      <span class="hljs-attr">"type"</span>: <span class="hljs-string">"selector"</span>,
      <span class="hljs-attr">"dimension"</span>: <span class="hljs-string">"tags"</span>,
      <span class="hljs-attr">"value"</span>: <span class="hljs-string">"t1"</span>
    },
    {
      <span class="hljs-attr">"type"</span>: <span class="hljs-string">"selector"</span>,
      <span class="hljs-attr">"dimension"</span>: <span class="hljs-string">"tags"</span>,
      <span class="hljs-attr">"value"</span>: <span class="hljs-string">"t3"</span>
    }
  ]
}
</code></pre>
<p>This &quot;selector&quot; filter would match row4 of the dataset above:</p>
<pre><code class="hljs">{
  <span class="hljs-attr">"type"</span>: <span class="hljs-string">"selector"</span>,
  <span class="hljs-attr">"dimension"</span>: <span class="hljs-string">"tags"</span>,
  <span class="hljs-attr">"value"</span>: <span class="hljs-literal">null</span>
}
</code></pre>
<h3><a class="anchor" aria-hidden="true" id="grouping"></a><a href="#grouping" aria-hidden="true" class="hash-link"><svg class="hash-link-icon" aria-hidden="true" height="16" version="1.1" viewBox="0 0 16 16" width="16"><path fill-rule="evenodd" d="M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z"></path></svg></a>Grouping</h3>
<p>topN and groupBy queries can group on multi-value dimensions. When grouping on a multi-value dimension, <em>all</em> values
from matching rows will be used to generate one group per value. This can be thought of as the equivalent to the
<code>UNNEST</code> operator used on an <code>ARRAY</code> type that many SQL dialects support. This means it's possible for a query to return
more groups than there are rows. For example, a topN on the dimension <code>tags</code> with filter <code>&quot;t1&quot; AND &quot;t3&quot;</code> would match
only row1, and generate a result with three groups: <code>t1</code>, <code>t2</code>, and <code>t3</code>. If you only need to include values that match
your filter, you can use a <a href="dimensionspecs.html#filtered-dimensionspecs">filtered dimensionSpec</a>. This can also
improve performance.</p>
<h3><a class="anchor" aria-hidden="true" id="example-groupby-query-with-no-filtering"></a><a href="#example-groupby-query-with-no-filtering" aria-hidden="true" class="hash-link"><svg class="hash-link-icon" aria-hidden="true" height="16" version="1.1" viewBox="0 0 16 16" width="16"><path fill-rule="evenodd" d="M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z"></path></svg></a>Example: GroupBy query with no filtering</h3>
<p>See <a href="groupbyquery.html">GroupBy querying</a> for details.</p>
<pre><code class="hljs css language-json">{
  <span class="hljs-attr">"queryType"</span>: <span class="hljs-string">"groupBy"</span>,
  <span class="hljs-attr">"dataSource"</span>: <span class="hljs-string">"test"</span>,
  <span class="hljs-attr">"intervals"</span>: [
    <span class="hljs-string">"1970-01-01T00:00:00.000Z/3000-01-01T00:00:00.000Z"</span>
  ],
  <span class="hljs-attr">"granularity"</span>: {
    <span class="hljs-attr">"type"</span>: <span class="hljs-string">"all"</span>
  },
  <span class="hljs-attr">"dimensions"</span>: [
    {
      <span class="hljs-attr">"type"</span>: <span class="hljs-string">"default"</span>,
      <span class="hljs-attr">"dimension"</span>: <span class="hljs-string">"tags"</span>,
      <span class="hljs-attr">"outputName"</span>: <span class="hljs-string">"tags"</span>
    }
  ],
  <span class="hljs-attr">"aggregations"</span>: [
    {
      <span class="hljs-attr">"type"</span>: <span class="hljs-string">"count"</span>,
      <span class="hljs-attr">"name"</span>: <span class="hljs-string">"count"</span>
    }
  ]
}
</code></pre>
<p>returns following result.</p>
<pre><code class="hljs css language-json">[
  {
    <span class="hljs-attr">"timestamp"</span>: <span class="hljs-string">"1970-01-01T00:00:00.000Z"</span>,
    <span class="hljs-attr">"event"</span>: {
      <span class="hljs-attr">"count"</span>: <span class="hljs-number">1</span>,
      <span class="hljs-attr">"tags"</span>: <span class="hljs-string">"t1"</span>
    }
  },
  {
    <span class="hljs-attr">"timestamp"</span>: <span class="hljs-string">"1970-01-01T00:00:00.000Z"</span>,
    <span class="hljs-attr">"event"</span>: {
      <span class="hljs-attr">"count"</span>: <span class="hljs-number">1</span>,
      <span class="hljs-attr">"tags"</span>: <span class="hljs-string">"t2"</span>
    }
  },
  {
    <span class="hljs-attr">"timestamp"</span>: <span class="hljs-string">"1970-01-01T00:00:00.000Z"</span>,
    <span class="hljs-attr">"event"</span>: {
      <span class="hljs-attr">"count"</span>: <span class="hljs-number">2</span>,
      <span class="hljs-attr">"tags"</span>: <span class="hljs-string">"t3"</span>
    }
  },
  {
    <span class="hljs-attr">"timestamp"</span>: <span class="hljs-string">"1970-01-01T00:00:00.000Z"</span>,
    <span class="hljs-attr">"event"</span>: {
      <span class="hljs-attr">"count"</span>: <span class="hljs-number">1</span>,
      <span class="hljs-attr">"tags"</span>: <span class="hljs-string">"t4"</span>
    }
  },
  {
    <span class="hljs-attr">"timestamp"</span>: <span class="hljs-string">"1970-01-01T00:00:00.000Z"</span>,
    <span class="hljs-attr">"event"</span>: {
      <span class="hljs-attr">"count"</span>: <span class="hljs-number">2</span>,
      <span class="hljs-attr">"tags"</span>: <span class="hljs-string">"t5"</span>
    }
  },
  {
    <span class="hljs-attr">"timestamp"</span>: <span class="hljs-string">"1970-01-01T00:00:00.000Z"</span>,
    <span class="hljs-attr">"event"</span>: {
      <span class="hljs-attr">"count"</span>: <span class="hljs-number">1</span>,
      <span class="hljs-attr">"tags"</span>: <span class="hljs-string">"t6"</span>
    }
  },
  {
    <span class="hljs-attr">"timestamp"</span>: <span class="hljs-string">"1970-01-01T00:00:00.000Z"</span>,
    <span class="hljs-attr">"event"</span>: {
      <span class="hljs-attr">"count"</span>: <span class="hljs-number">1</span>,
      <span class="hljs-attr">"tags"</span>: <span class="hljs-string">"t7"</span>
    }
  }
]
</code></pre>
<p>notice how original rows are &quot;exploded&quot; into multiple rows and merged.</p>
<h3><a class="anchor" aria-hidden="true" id="example-groupby-query-with-a-selector-query-filter"></a><a href="#example-groupby-query-with-a-selector-query-filter" aria-hidden="true" class="hash-link"><svg class="hash-link-icon" aria-hidden="true" height="16" version="1.1" viewBox="0 0 16 16" width="16"><path fill-rule="evenodd" d="M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z"></path></svg></a>Example: GroupBy query with a selector query filter</h3>
<p>See <a href="filters.html">query filters</a> for details of selector query filter.</p>
<pre><code class="hljs css language-json">{
  <span class="hljs-attr">"queryType"</span>: <span class="hljs-string">"groupBy"</span>,
  <span class="hljs-attr">"dataSource"</span>: <span class="hljs-string">"test"</span>,
  <span class="hljs-attr">"intervals"</span>: [
    <span class="hljs-string">"1970-01-01T00:00:00.000Z/3000-01-01T00:00:00.000Z"</span>
  ],
  <span class="hljs-attr">"filter"</span>: {
    <span class="hljs-attr">"type"</span>: <span class="hljs-string">"selector"</span>,
    <span class="hljs-attr">"dimension"</span>: <span class="hljs-string">"tags"</span>,
    <span class="hljs-attr">"value"</span>: <span class="hljs-string">"t3"</span>
  },
  <span class="hljs-attr">"granularity"</span>: {
    <span class="hljs-attr">"type"</span>: <span class="hljs-string">"all"</span>
  },
  <span class="hljs-attr">"dimensions"</span>: [
    {
      <span class="hljs-attr">"type"</span>: <span class="hljs-string">"default"</span>,
      <span class="hljs-attr">"dimension"</span>: <span class="hljs-string">"tags"</span>,
      <span class="hljs-attr">"outputName"</span>: <span class="hljs-string">"tags"</span>
    }
  ],
  <span class="hljs-attr">"aggregations"</span>: [
    {
      <span class="hljs-attr">"type"</span>: <span class="hljs-string">"count"</span>,
      <span class="hljs-attr">"name"</span>: <span class="hljs-string">"count"</span>
    }
  ]
}
</code></pre>
<p>returns following result.</p>
<pre><code class="hljs css language-json">[
  {
    <span class="hljs-attr">"timestamp"</span>: <span class="hljs-string">"1970-01-01T00:00:00.000Z"</span>,
    <span class="hljs-attr">"event"</span>: {
      <span class="hljs-attr">"count"</span>: <span class="hljs-number">1</span>,
      <span class="hljs-attr">"tags"</span>: <span class="hljs-string">"t1"</span>
    }
  },
  {
    <span class="hljs-attr">"timestamp"</span>: <span class="hljs-string">"1970-01-01T00:00:00.000Z"</span>,
    <span class="hljs-attr">"event"</span>: {
      <span class="hljs-attr">"count"</span>: <span class="hljs-number">1</span>,
      <span class="hljs-attr">"tags"</span>: <span class="hljs-string">"t2"</span>
    }
  },
  {
    <span class="hljs-attr">"timestamp"</span>: <span class="hljs-string">"1970-01-01T00:00:00.000Z"</span>,
    <span class="hljs-attr">"event"</span>: {
      <span class="hljs-attr">"count"</span>: <span class="hljs-number">2</span>,
      <span class="hljs-attr">"tags"</span>: <span class="hljs-string">"t3"</span>
    }
  },
  {
    <span class="hljs-attr">"timestamp"</span>: <span class="hljs-string">"1970-01-01T00:00:00.000Z"</span>,
    <span class="hljs-attr">"event"</span>: {
      <span class="hljs-attr">"count"</span>: <span class="hljs-number">1</span>,
      <span class="hljs-attr">"tags"</span>: <span class="hljs-string">"t4"</span>
    }
  },
  {
    <span class="hljs-attr">"timestamp"</span>: <span class="hljs-string">"1970-01-01T00:00:00.000Z"</span>,
    <span class="hljs-attr">"event"</span>: {
      <span class="hljs-attr">"count"</span>: <span class="hljs-number">1</span>,
      <span class="hljs-attr">"tags"</span>: <span class="hljs-string">"t5"</span>
    }
  }
]
</code></pre>
<p>You might be surprised to see inclusion of &quot;t1&quot;, &quot;t2&quot;, &quot;t4&quot; and &quot;t5&quot; in the results. It happens because query filter is
applied on the row before explosion. For multi-value dimensions, selector filter for &quot;t3&quot; would match row1 and row2,
after which exploding is done. For multi-value dimensions, query filter matches a row if any individual value inside
the multiple values matches the query filter.</p>
<h3><a class="anchor" aria-hidden="true" id="example-groupby-query-with-a-selector-query-filter-and-additional-filter-in-dimensions-attributes"></a><a href="#example-groupby-query-with-a-selector-query-filter-and-additional-filter-in-dimensions-attributes" aria-hidden="true" class="hash-link"><svg class="hash-link-icon" aria-hidden="true" height="16" version="1.1" viewBox="0 0 16 16" width="16"><path fill-rule="evenodd" d="M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z"></path></svg></a>Example: GroupBy query with a selector query filter and additional filter in &quot;dimensions&quot; attributes</h3>
<p>To solve the problem above and to get only rows for &quot;t3&quot; returned, you would have to use a &quot;filtered dimension spec&quot; as
in the query below.</p>
<p>See section on filtered dimensionSpecs in <a href="dimensionspecs.html#filtered-dimensionspecs">dimensionSpecs</a> for details.</p>
<pre><code class="hljs css language-json">{
  <span class="hljs-attr">"queryType"</span>: <span class="hljs-string">"groupBy"</span>,
  <span class="hljs-attr">"dataSource"</span>: <span class="hljs-string">"test"</span>,
  <span class="hljs-attr">"intervals"</span>: [
    <span class="hljs-string">"1970-01-01T00:00:00.000Z/3000-01-01T00:00:00.000Z"</span>
  ],
  <span class="hljs-attr">"filter"</span>: {
    <span class="hljs-attr">"type"</span>: <span class="hljs-string">"selector"</span>,
    <span class="hljs-attr">"dimension"</span>: <span class="hljs-string">"tags"</span>,
    <span class="hljs-attr">"value"</span>: <span class="hljs-string">"t3"</span>
  },
  <span class="hljs-attr">"granularity"</span>: {
    <span class="hljs-attr">"type"</span>: <span class="hljs-string">"all"</span>
  },
  <span class="hljs-attr">"dimensions"</span>: [
    {
      <span class="hljs-attr">"type"</span>: <span class="hljs-string">"listFiltered"</span>,
      <span class="hljs-attr">"delegate"</span>: {
        <span class="hljs-attr">"type"</span>: <span class="hljs-string">"default"</span>,
        <span class="hljs-attr">"dimension"</span>: <span class="hljs-string">"tags"</span>,
        <span class="hljs-attr">"outputName"</span>: <span class="hljs-string">"tags"</span>
      },
      <span class="hljs-attr">"values"</span>: [<span class="hljs-string">"t3"</span>]
    }
  ],
  <span class="hljs-attr">"aggregations"</span>: [
    {
      <span class="hljs-attr">"type"</span>: <span class="hljs-string">"count"</span>,
      <span class="hljs-attr">"name"</span>: <span class="hljs-string">"count"</span>
    }
  ]
}
</code></pre>
<p>returns the following result.</p>
<pre><code class="hljs css language-json">[
  {
    <span class="hljs-attr">"timestamp"</span>: <span class="hljs-string">"1970-01-01T00:00:00.000Z"</span>,
    <span class="hljs-attr">"event"</span>: {
      <span class="hljs-attr">"count"</span>: <span class="hljs-number">2</span>,
      <span class="hljs-attr">"tags"</span>: <span class="hljs-string">"t3"</span>
    }
  }
]
</code></pre>
<p>Note that, for groupBy queries, you could get similar result with a <a href="having.html">having spec</a> but using a filtered
dimensionSpec is much more efficient because that gets applied at the lowest level in the query processing pipeline.
Having specs are applied at the outermost level of groupBy query processing.</p>
</span></div></article></div><div class="docs-prevnext"><a class="docs-prev button" href="/docs/0.20.0/querying/lookups.html"><span class="arrow-prev">← </span><span>Lookups</span></a><a class="docs-next button" href="/docs/0.20.0/querying/multitenancy.html"><span>Multitenancy</span><span class="arrow-next"> →</span></a></div></div></div><nav class="onPageNav"><ul class="toc-headings"><li><a href="#querying-multi-value-dimensions">Querying multi-value dimensions</a><ul class="toc-headings"><li><a href="#filtering">Filtering</a></li><li><a href="#grouping">Grouping</a></li><li><a href="#example-groupby-query-with-no-filtering">Example: GroupBy query with no filtering</a></li><li><a href="#example-groupby-query-with-a-selector-query-filter">Example: GroupBy query with a selector query filter</a></li><li><a href="#example-groupby-query-with-a-selector-query-filter-and-additional-filter-in-dimensions-attributes">Example: GroupBy query with a selector query filter and additional filter in &quot;dimensions&quot; attributes</a></li></ul></li></ul></nav></div><footer class="nav-footer druid-footer" id="footer"><div class="container"><div class="text-center"><p><a href="/technology">Technology</a> · <a href="/use-cases">Use Cases</a> · <a href="/druid-powered">Powered by Druid</a> · <a href="/docs/0.20.0/latest">Docs</a> · <a href="/community/">Community</a> · <a href="/downloads.html">Download</a> · <a href="/faq">FAQ</a></p></div><div class="text-center"><a title="Join the user group" href="https://groups.google.com/forum/#!forum/druid-user" target="_blank"><span class="fa fa-comments"></span></a> · <a title="Follow Druid" href="https://twitter.com/druidio" target="_blank"><span class="fab fa-twitter"></span></a> · <a title="Download via Apache" href="https://www.apache.org/dyn/closer.cgi?path=/incubator/druid/{{ site.druid_versions[0].versions[0].version }}/apache-druid-{{ site.druid_versions[0].versions[0].version }}-bin.tar.gz" target="_blank"><span class="fas fa-feather"></span></a> · <a title="GitHub" href="https://github.com/apache/druid" target="_blank"><span class="fab fa-github"></span></a></div><div class="text-center license">Copyright © 2019 <a href="https://www.apache.org/" target="_blank">Apache Software Foundation</a>.<br/>Except where otherwise noted, licensed under <a rel="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA 4.0</a>.<br/>Apache Druid, Druid, and the Druid logo are either registered trademarks or trademarks of The Apache Software Foundation in the United States and other countries.</div></div></footer></div><script type="text/javascript" src="https://cdn.jsdelivr.net/docsearch.js/1/docsearch.min.js"></script><script>
                document.addEventListener('keyup', function(e) {
                  if (e.target !== document.body) {
                    return;
                  }
                  // keyCode for '/' (slash)
                  if (e.keyCode === 191) {
                    const search = document.getElementById('search_input_react');
                    search && search.focus();
                  }
                });
              </script><script>
              var search = docsearch({
                
                apiKey: '2de99082a9f38e49dfaa059bbe4c901d',
                indexName: 'apache_druid',
                inputSelector: '#search_input_react',
                algoliaOptions: {"facetFilters":["language:en","version:0.20.0"]}
              });
            </script></body></html>