DatasourceMetadata queries

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 Context	no

The format of the result is:

[ {
  "timestamp" : "2013-05-09T18:24:00.000Z",
  "result" : {
    "maxIngestedEventTime" : "2013-05-09T18:24:09.007Z"
  }
} ]