[DRILL-1629] Cast issue during query

• Type: Bug
• Status: Open
• Priority: Minor
• Resolution: Unresolved
• Fix Version/s: Future
• Component/s: Query Planning & Optimization
• Assignee: Unassigned
• Reporter: Tomer Shiran
• Created: 03/Nov/14 05:25
• Updated: 01/Oct/15 16:37

Description

Imported Yelp user.json file into a local MongoDB instance (via mongoimport). Ran the following query to find the names of the users who had the most reviews:

0: jdbc:drill:zk=local> SELECT u.user_id, u.name, count(*) reviews FROM mongo.yelp.users u, dfs.yelp.`yelp_academic_dataset_review.json` r WHERE u.user_id = r.user_id GROUP BY u.user_id, u.name ORDER BY reviews DESC LIMIT 10;
Query failed: Failure while running fragment. Failure finding function that runtime code generation expected.  Signature: compare_to( VARCHAR:OPTIONALINT:OPTIONAL,  ) returns INT:REQUIRED [c796f1fb-b73a-49e8-8b4a-ed973d89b7d3]

Error: exception while executing query: Failure while trying to get next result batch. (state=,code=0)

Here's the explain plan:

0: jdbc:drill:zk=local> EXPLAIN PLAN FOR SELECT u.user_id, u.name, count(*) reviews FROM mongo.yelp.users u, dfs.yelp.`yelp_academic_dataset_review.json` r WHERE u.user_id = r.user_id GROUP BY u.user_id, u.name ORDER BY reviews DESC LIMIT 10;
+------------+------------+
|    text    |    json    |
+------------+------------+
| 00-00    Screen
00-01      Project(user_id=[$0], name=[$1], reviews=[$2])
00-02        SelectionVectorRemover
00-03          Limit(fetch=[10])
00-04            SingleMergeExchange(sort0=[2 DESC])
01-01              SelectionVectorRemover
01-02                TopN(limit=[10])
01-03                  HashToRandomExchange(dist0=[[$2]])
02-01                    HashAgg(group=[{0, 1}], reviews=[COUNT()])
02-02                      Project(user_id=[$0], name=[$1])
02-03                        HashJoin(condition=[=($0, $2)], joinType=[inner])
02-05                          HashToRandomExchange(dist0=[[$0]])
03-01                            Scan(groupscan=[MongoGroupScan [MongoScanSpec=MongoScanSpec [dbName=yelp, collectionName=users, filters=null], columns=[SchemaPath [`user_id`], SchemaPath [`name`]]]])
02-04                          HashToRandomExchange(dist0=[[$0]])
04-01                            Project(T8¦¦*=[$0])
04-02                              Project(T8¦¦*=[$0], T8¦¦user_id=[$ |
+------------+------------+
1 row selected (0.42 seconds)