[DRILL-5088] Error when reading DBRef column

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 1.10.0
• Component/s: Execution - Data Types

Environment

drill 1.9.0
mongo 3.2

• Assignee: Chunhui Shi
• Reporter: Guillaume Champion
• Reviewer: Gautam Parai
• Created: 01/Dec/16 16:20
• Updated: 28/Mar/17 23:49
• Resolved: 25/Feb/17 07:24

Description

In a mongo database with DBRef, when a DBRef is inserted in the first line of a mongo's collection drill query failed :

0: jdbc:drill:zk=local> select * from mongo.mydb.contact2;
Error: SYSTEM ERROR: CodecConfigurationException: Can't find a codec for class com.mongodb.DBRef.

Simple example to reproduce:
In mongo instance

db.contact2.drop();
db.contact2.insert({ "_id" : ObjectId("582081d96b69060001fd8938"), "account" : DBRef("contact", ObjectId("999cbf116b69060001fd8611")) });

In drill :

0: jdbc:drill:zk=local> select * from mongo.mydb.contact2;
Error: SYSTEM ERROR: CodecConfigurationException: Can't find a codec for class com.mongodb.DBRef.


[Error Id: 2944d766-e483-4453-a706-3d481397b186 on Analytics-Biznet:31010] (state=,code=0)

If the first line doesn't contain de DBRef, drill will querying correctly :
In a mongo instance :

db.contact2.drop();
db.contact2.insert({ "_id" : ObjectId("582081d96b69060001fd8939") });
db.contact2.insert({ "_id" : ObjectId("582081d96b69060001fd8938"), "account" : DBRef("contact", ObjectId("999cbf116b69060001fd8611")) });

In drill :

0: jdbc:drill:zk=local> select * from mongo.mydb.contact2;
+--------------------------------------+---------------------------------------------------------------+
|                 _id                  |                            account                            |
+--------------------------------------+---------------------------------------------------------------+
| {"$oid":"582081d96b69060001fd8939"}  | {"$id":{}}                                                    |
| {"$oid":"582081d96b69060001fd8938"}  | {"$ref":"contact","$id":{"$oid":"999cbf116b69060001fd8611"}}  |
+--------------------------------------+---------------------------------------------------------------+
2 rows selected (0,563 seconds)

Issue Links

• is blocked by: DRILL-5196 Could not run a single MongoDB unit test case through command line or IDE
• links to: GitHub Pull Request #702