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new e395e30cd User Guide: Add `EXPLAIN` to SQL reference (#3767)
e395e30cd is described below
commit e395e30cd972ba9684020a4167c12d1424675698
Author: unvalley <[email protected]>
AuthorDate: Mon Oct 10 23:56:21 2022 +0900
User Guide: Add `EXPLAIN` to SQL reference (#3767)
* docs: add explain.md
* docs: add explain to sql index
* docs: describe explain at the beginning
* docs: mention VERBOSE
---
docs/source/user-guide/sql/explain.md | 71 +++++++++++++++++++++++++++++++++++
docs/source/user-guide/sql/index.rst | 1 +
2 files changed, 72 insertions(+)
diff --git a/docs/source/user-guide/sql/explain.md
b/docs/source/user-guide/sql/explain.md
new file mode 100644
index 000000000..08cc8be75
--- /dev/null
+++ b/docs/source/user-guide/sql/explain.md
@@ -0,0 +1,71 @@
+<!---
+ Licensed to the Apache Software Foundation (ASF) under one
+ or more contributor license agreements. See the NOTICE file
+ distributed with this work for additional information
+ regarding copyright ownership. The ASF licenses this file
+ to you under the Apache License, Version 2.0 (the
+ "License"); you may not use this file except in compliance
+ with the License. You may obtain a copy of the License at
+
+ http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing,
+ software distributed under the License is distributed on an
+ "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ KIND, either express or implied. See the License for the
+ specific language governing permissions and limitations
+ under the License.
+-->
+
+# EXPLAIN
+
+The `EXPLAIN` command shows the logical and physical execution plan for the
specified SQL statement.
+
+<pre>
+EXPLAIN [ANALYZE] [VERBOSE] statement
+</pre>
+
+## EXPLAIN
+
+Shows the execution plan of a statement.
+If you need more details output, try to use `EXPLAIN VERBOSE`.
+
+```sql
+EXPLAIN SELECT SUM(x) FROM table GROUP BY b;
++---------------+----------------------------------------------------------------------------------------------------------------------------------------------------------------+
+| plan_type | plan
|
++---------------+----------------------------------------------------------------------------------------------------------------------------------------------------------------+
+| logical_plan | Projection: #SUM(table.x)
|
+| | Aggregate: groupBy=[[#table.b]], aggr=[[SUM(#table.x)]]
|
+| | TableScan: table projection=[x, b]
|
+| physical_plan | ProjectionExec: expr=[SUM(table.x)@1 as SUM(table.x)]
|
+| | AggregateExec: mode=FinalPartitioned, gby=[b@0 as b],
aggr=[SUM(table.x)]
|
+| | CoalesceBatchesExec: target_batch_size=4096
|
+| | RepartitionExec: partitioning=Hash([Column { name:
"b", index: 0 }], 16)
|
+| | AggregateExec: mode=Partial, gby=[b@1 as b],
aggr=[SUM(table.x)]
|
+| | RepartitionExec: partitioning=RoundRobinBatch(16)
|
+| | CsvExec: source=Path(/tmp/table.csv:
[/tmp/table.csv]), has_header=false, limit=None, projection=[x, b]
|
+| |
|
++---------------+----------------------------------------------------------------------------------------------------------------------------------------------------------------+
+```
+
+## EXPLAIN ANALYZE
+
+Shows the execution plan and metrics of a statment.
+If you need more information output, try to use `EXPLAIN ANALYZE VERBOSE`.
+
+```sql
+EXPLAIN ANALYZE SELECT SUM(x) FROM table GROUP BY b;
++-------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------+
+| plan_type | plan
|
++-------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------+
+| Plan with Metrics | CoalescePartitionsExec, metrics=[]
|
+| | ProjectionExec: expr=[SUM(table.x)@1 as SUM(x)],
metrics=[]
|
+| | HashAggregateExec: mode=FinalPartitioned, gby=[b@0
as b], aggr=[SUM(x)], metrics=[outputRows=2]
|
+| | CoalesceBatchesExec: target_batch_size=4096,
metrics=[]
|
+| | RepartitionExec: partitioning=Hash([Column {
name: "b", index: 0 }], 16), metrics=[sendTime=839560, fetchTime=122528525,
repartitionTime=5327877] |
+| | HashAggregateExec: mode=Partial, gby=[b@1 as
b], aggr=[SUM(x)], metrics=[outputRows=2]
|
+| | RepartitionExec:
partitioning=RoundRobinBatch(16), metrics=[fetchTime=5660489,
repartitionTime=0, sendTime=8012] |
+| | CsvExec: source=Path(/tmp/table.csv:
[/tmp/table.csv]), has_header=false, metrics=[]
|
++-------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------+
+```
diff --git a/docs/source/user-guide/sql/index.rst
b/docs/source/user-guide/sql/index.rst
index ff98d95f3..373d60eb1 100644
--- a/docs/source/user-guide/sql/index.rst
+++ b/docs/source/user-guide/sql/index.rst
@@ -25,6 +25,7 @@ SQL Reference
select
subqueries
ddl
+ explain
information_schema
aggregate_functions
scalar_functions
