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Posted to commits@druid.apache.org by GitBox <gi...@apache.org> on 2022/09/06 17:11:29 UTC
[GitHub] [druid] vtlim commented on a diff in pull request #13033: remove mentions of DruidQueryRel from docs
vtlim commented on code in PR #13033:
URL: https://github.com/apache/druid/pull/13033#discussion_r963970313
##########
docs/querying/sql-translation.md:
##########
@@ -63,37 +63,137 @@ appreciated.
## Interpreting EXPLAIN PLAN output
The [EXPLAIN PLAN](sql.md#explain-plan) functionality can help you understand how a given SQL query will
-be translated to native. For simple queries that do not involve subqueries or joins, the output of EXPLAIN PLAN
-is easy to interpret. The native query that will run is embedded as JSON inside a "DruidQueryRel" line:
-
-```
-> EXPLAIN PLAN FOR SELECT COUNT(*) FROM wikipedia
-
-DruidQueryRel(query=[{"queryType":"timeseries","dataSource":"wikipedia","intervals":"-146136543-09-08T08:23:32.096Z/146140482-04-24T15:36:27.903Z","granularity":"all","aggregations":[{"type":"count","name":"a0"}]}], signature=[{a0:LONG}])
+be translated to native. The native queries that will run are returned as a JSON array in the PLAN column:
+
+```sql
+EXPLAIN PLAN FOR
+SELECT
+ channel,
+ COUNT(*)
+FROM wikipedia
+WHERE channel IN (SELECT page FROM wikipedia GROUP BY page ORDER BY COUNT(*) DESC LIMIT 10)
+GROUP BY channel
```
-For more complex queries that do involve subqueries or joins, EXPLAIN PLAN is somewhat more difficult to interpret.
-For example, consider this query:
+Returns the following plan:
Review Comment:
```suggestion
The EXPLAIN PLAN statement returns the following plan:
```
##########
docs/querying/sql-translation.md:
##########
@@ -63,37 +63,137 @@ appreciated.
## Interpreting EXPLAIN PLAN output
The [EXPLAIN PLAN](sql.md#explain-plan) functionality can help you understand how a given SQL query will
-be translated to native. For simple queries that do not involve subqueries or joins, the output of EXPLAIN PLAN
-is easy to interpret. The native query that will run is embedded as JSON inside a "DruidQueryRel" line:
-
-```
-> EXPLAIN PLAN FOR SELECT COUNT(*) FROM wikipedia
-
-DruidQueryRel(query=[{"queryType":"timeseries","dataSource":"wikipedia","intervals":"-146136543-09-08T08:23:32.096Z/146140482-04-24T15:36:27.903Z","granularity":"all","aggregations":[{"type":"count","name":"a0"}]}], signature=[{a0:LONG}])
+be translated to native. The native queries that will run are returned as a JSON array in the PLAN column:
Review Comment:
```suggestion
be translated to native. The native queries that will run are returned as a JSON array in the PLAN column. For example, consider the following query:
```
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