EXPLAIN FRAGMENTS
Shows the distributed execution plan of a SQL statement.
This command transforms the execution plan of a SQL statement into plan fragments where you can see the process of retrieving the data you need from Databend.
Syntax
EXPLAIN FRAGMENTS <statement>
Examples
EXPLAIN FRAGMENTS select COUNT() from numbers(10) GROUP BY number % 3;
+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| explain |
+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Fragment 0: |
| DataExchange: Shuffle |
| AggregatorPartial: groupBy=[[(number % 3)]], aggr=[[COUNT()]] |
| Expression: (number % 3):UInt8 (Before GroupBy) |
| ReadDataSource: scan schema: [number:UInt64], statistics: [read_rows: 10, read_bytes: 80, partitions_scanned: 1, partitions_total: 1], push_downs: [projections: [0]] |
| |
| Fragment 2: |
| DataExchange: Merge |
| Projection: COUNT():UInt64 |
| AggregatorFinal: groupBy=[[(number % 3)]], aggr=[[COUNT()]] |
| Remote[receive fragment: 0] |
+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
11 rows in set (0.02 sec)
Read 0 rows, 0.00 B in 0.003 sec., 0 rows/sec., 0.00 B/sec.