Apache Drill - Querying Parquet Files

https://www.tutorialspoint.com/apache_drill/apache_drill_querying_parquet_files.htm

 

Parquet is a columnar storage format. Apache Drill uses Parquet format for easy, fast and efficient access.

Create a Table

Before moving to create a table in parquet, you must change the Drill storage format using the following command.

Query

0: jdbc:drill:zk = local> alter session set `store.format`= 'parquet';

Result

+-------+------------------------+
|  ok   |        summary         |
+-------+------------------------+
| true  | store.format updated.  |
+———----+------------------------+

You can create a table using the following syntax.

Query

0: jdbc:drill:zk = local> create table dfs.tmp.`/Users/../workspace` as select * from
   dfs.`/Users/../workspace/Drill-samples/student_list.json`;

Result

+----------+---------------------------+
| Fragment | Number of records written |
+----------+---------------------------+
|   0_0    |            10             |
+----------+---------------------------+

To see the table contents, type-in the following query −

Query

0: jdbc:drill:zk = local> select * from dfs.tmp.`/Users/../workspace`;

Result

+-----+-------+-----+--------+----------+-------+-------+-------+-------------------+---------+
| ID  | name  | age | gender | standard | mark1 | mark2 | mark3 |      addr         | pincode |
+-----+-------+-----+--------+----------+-------+-------+-------+-------------------+---------+
| 001 | Adam  | 12  |  male  |   six    |  70   |  50   |  60   | 23 new street     | 111222  |
| 002 | Amit  | 12  |  male  |   six    |  40   |  50   |  40   | 12 old street     | 111222  |
| 003 | Bob   | 12  |  male  |   six    |  60   |  80   |  70   | 10 cross street   | 111222  |
| 004 | David | 12  |  male  |   six    |  50   |  70   |  70   | 15 express avenue | 111222  |
| 005 | Esha  | 12  | female |   six    |  70   |  60   |  65   | 20 garden street  | 111222  |
| 006 | Ganga | 12  | female |   six    |  100  |  95   |  98   | 25 north street   | 111222  |
| 007 | Jack  | 13  |  male  |   six    |  55   |  45   |  45   | 2 park street     | 111222  |
| 008 | Leena | 12  | female |   six    |  90   |  85   |  95   | 24 south street   | 111222  |
| 009 | Mary  | 13  | female |   six    |  75   |  85   |  90   | 5 west street     | 111222  |
| 010 | Peter | 13  | female |   six    |  80   |  85   |  88   | 16 park avenue    | 111222  |
+-----+-------+-----+--------+----------+-------+-------+-------+-------------------+---------+