Checking query execution

You can determine if query vectorization occurred during execution by running the EXPLAIN VECTORIZATION query statement.

Start Hive from Beeline.
```
$ hive
```
Set hive.explain.user to false to see vector values.
```
SET hive.explain.user=false;
```

Run the EXPLAIN VECTORIZATION statement on the query you want CDP to process using vectorization.

EXPLAIN VECTORIZATION SELECT COUNT(*) FROM employees where emp_no>10;

The following output confirms that vectorization occurs:

+----------------------------------------------------+
|                      Explain                       |
+----------------------------------------------------+
| Plan optimized by CBO.                             |
|                                                    |
| Vertex dependency in root stage                    |
| Reducer 2 <- Map 1 [CUSTOM_SIMPLE_EDGE] *vectorized* |
|       File Output Operator [FS_14]                 |
|         Group By Operator [GBY_13] (rows=1 width=12) |
|           Output:["_col0"],aggregations:["count(VALUE._col0)"] |
|         <-Map 1 [CUSTOM_SIMPLE_EDGE] vectorized    | 
|           PARTITION_ONLY_SHUFFLE [RS_12]           |
|             Group By Operator [GBY_11] (rows=1 width=12) |
|               Output:["_col0"],aggregations:["count()"] |
|               Select Operator [SEL_10] (rows=1 width=4) |
|                 Filter Operator [FIL_9] (rows=1 width=4) |
|                   predicate:(emp_no > 10)          |
|                   TableScan [TS_0] (rows=1 width=4) |
|                     default@employees,employees,Tbl:COMPLETE,Col:NONE,Output:["emp_no"] |
|                                                    |
+----------------------------------------------------+
23 rows selected (1.542 seconds)