:::info Apache Druid supports two query languages: Druid SQL and native queries. This document describes a query type that is only available in the native language. :::
Data Source Metadata queries return metadata information for a dataSource. These queries return information about:
maxIngestedEventTime: The timestamp of the latest ingested event for the dataSource. For realtime datasources, this may be later than MAX(__time) if queryGranularity is being used. For non-realtime datasources, this is equivalent to MAX(__time).The grammar for these queries is:
{ "queryType" : "dataSourceMetadata", "dataSource": "sample_datasource" }
There are 2 main parts to a Data Source Metadata query:
| property | description | required? |
|---|---|---|
| queryType | This String should always be “dataSourceMetadata”; this is the first thing Apache Druid looks at to figure out how to interpret the query | yes |
| dataSource | A String or Object defining the data source to query, very similar to a table in a relational database. See DataSource for more information. | yes |
| context | See Query context reference | no |
The format of the result is:
[ { "timestamp" : "2013-05-09T18:24:00.000Z", "result" : { "maxIngestedEventTime" : "2013-05-09T18:24:09.007Z" } } ]