Apache
/
druid
mirror of https://github.com/apache/druid.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

Update SQL doc for planning change (#7415)

This commit is contained in:
Justin Borromeo 2019-04-05 15:14:07 -07:00 committed by Clint Wylie
parent 76b4a5c62e
commit e23fd41fa7
1 changed files with 1 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
docs/content/querying/sql.md
View File

@ -324,9 +324,7 @@ converted to zeroes).
## Query execution ## Query execution
Queries without aggregations will use Druid's [Scan](scan-query.html) or [Select](select-query.html) native query types. Queries without aggregations will use Druid's [Scan](scan-query.html) native query type.
Scan is used whenever possible, as it is generally higher performance and more efficient than Select. However, Select
is used in one case: when the query includes an `ORDER BY __time`, since Scan does not have a sorting feature.
Aggregation queries (using GROUP BY, DISTINCT, or any aggregation functions) will use one of Druid's three native Aggregation queries (using GROUP BY, DISTINCT, or any aggregation functions) will use one of Druid's three native
aggregation query types. Two (Timeseries and TopN) are specialized for specific types of aggregations, whereas the other aggregation query types. Two (Timeseries and TopN) are specialized for specific types of aggregations, whereas the other