[DRILL-4903] Implicit columns are shown when Jdbc plugin is enabled

• Type: Bug
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 1.8.0
• Fix Version/s: 1.11.0
• Assignee: Arina Ielchiieva
• Reporter: Arina Ielchiieva
• Created: 23/Sep/16 14:01
• Updated: 27/Jun/17 13:41
• Resolved: 27/Jun/17 13:41

Description

When any Jdbc Plugin enabled (ex: MySql) implicit columns are returned as part of select * query.
Simple json:

{id: 1, name: "Bob"}

When Jdbc plugin is enabled:

0: jdbc:drill:zk=local> select * from dfs.`/home/osboxes/files/simple.json`;
+----------------------------------+----------------------+--------------+---------+-----+-------+
|               fqn                |       filepath       |   filename   | suffix  | id  | name  |
+----------------------------------+----------------------+--------------+---------+-----+-------+
| /home/osboxes/files/simple.json  | /home/osboxes/files  | simple.json  | json    | 1   | Bob   |
+----------------------------------+----------------------+--------------+---------+-----+-------+
1 row selected (0.203 seconds)
0: jdbc:drill:zk=local> explain plan for select * from dfs.`/home/osboxes/files/simple.json`;
+------+------+
| text | json |
+------+------+
| 00-00    Screen
00-01      Scan(groupscan=[EasyGroupScan [selectionRoot=file:/home/osboxes/files/simple.json, numFiles=1, columns=[`*`], files=[file:/home/osboxes/files/simple.json]]])

When Jdbc plugin is disabled:

0: jdbc:drill:zk=local> select * from dfs.`/home/osboxes/files/simple.json`;
+-----+-------+
| id  | name  |
+-----+-------+
| 1   | Bob   |
+-----+-------+
1 row selected (0.547 seconds)
0: jdbc:drill:zk=local> explain plan for select * from dfs.`/home/osboxes/files/simple.json`;
+------+------+
| text | json |
+------+------+
| 00-00    Screen
00-01      Project(*=[$0])
00-02        Scan(groupscan=[EasyGroupScan [selectionRoot=file:/home/osboxes/files/simple.json, numFiles=1, columns=[`*`], files=[file:/home/osboxes/files/simple.json]]])

The problem is that implicit columns are removed from queries with select * clause during project stage. But JdbcStoragePlugin adds ProjectRemoveRules.class to rules which simplifies query plan and removes project stage.

https://github.com/apache/drill/blob/master/contrib/storage-jdbc/src/main/java/org/apache/drill/exec/store/jdbc/JdbcStoragePlugin.java#L140

Issue Links

• relates to: DRILL-5538 Create TopProject with validatedNodeType after PHYSICAL phase