Apache/druid
1
0
Fork 0
mirror of https://github.com/apache/druid.git synced 2025-02-08 11:05:05 +00:00
Code Issues Packages Projects Releases Wiki Activity
druid/docs/content/querying/datasource.md
Nishant 573aa96bd6 fix #1727 - Union bySegment queries fix 
Fixes #1727.
revert to doing merging for results for union queries on broker.

revert unrelated changes

Add test for union query runner

Add test

remove unused imports

fix imports

fix renamed file

fix test

update docs.
2015-09-29 23:32:36 +05:30

1.0 KiB
Raw Blame History

layout
doc_page

Datasources

A data source is the Druid equivalent of a database table. However, a query can also masquerade as a data source, providing subquery-like functionality. Query data sources are currently supported only by GroupBy queries.

Table Data Source

The table data source is the most common type. It's represented by a string, or by the full structure:

{
	"type": "table",
	"name": "<string_value>"
}

Union Data Source

This data source unions two or more table data sources.

{
       "type": "union",
       "dataSources": ["<string_value1>", "<string_value2>", "<string_value3>", ... ]
}

Note that the data sources being unioned should have the same schema. Union Queries should be always sent to the broker/router node and are NOT supported directly by the historical nodes.

Query Data Source

This is used for nested groupBys and is only currently supported for groupBys.

{
	"type": "query",
	"query": {
		"type": "groupBy",
		...
	}
}