[DRILL-7698] RDBMS Plugin Not Returning Results from Presto

• Type: Bug
• Status: Accepted
• Priority: Blocker
• Resolution: Unresolved
• Affects Version/s: 1.18.0
• Component/s: Storage - JDBC
• Assignee: Unassigned
• Reporter: Charles Givre
• Created: 12/Apr/20 19:03
• Updated: 08/May/20 00:33

Description

Using the RDBMS storage plugin, Drill is unable to connect to Presto. More specifically, Drill seems to be connecting and sending queries to Presto, but then nothing happens with the query results.

I verified the configuration using DBBeaver and was able to successfully query Presto. See screenshot below for config.

Presto ships with a few sample databases as shown below, and these should be visible in Drill but are not.

From the logs below, Presto is clearly receiving the queries from Drill, and the queries are returning results, but Drill seems to be dropping the results. While this may seem like a silly exercise, querying Presto from Drill, the fact that it didn't work makes me think we may have a bug in the JDBC Storage Plugin.

Steps to Reproduce

1. Download and start Docker container with Presto.
2. Download Presto JDBC driver (https://prestodb.io/download.html) and copy to Drill classpath.
3. Create RDBMS storage plugin instance using default config below:

{
  "type": "jdbc",
  "driver": "io.prestosql.jdbc.PrestoDriver",
  "url": "jdbc:presto://localhost:8080/tpch/sf1",
  "username": "user",
  "password": null,
  "caseInsensitiveTableNames": true,
  "sourceParameters": {},
  "enabled": true
}

4. Execute a SHOW DATABASES query and you will see that no presto related results are returned. Various queries to the INFORMATION SCHEMA reveal the same thing.