[SPARK-47123] JDBCRDD does not correctly handle errors in getQueryOutputSchema

• Type: Bug
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 3.5.0, 4.0.0
• Fix Version/s: 4.0.0
• Component/s: Spark Core
• Labels: pull-request-available
• Assignee: Pablo Langa Blanco
• Reporter: Pablo Langa Blanco
• Created: 21/Feb/24 23:23
• Updated: 23/Feb/24 00:14
• Resolved: 23/Feb/24 00:14

Description

If there is an error executing statement.executeQuery(), it's possible that another error in one of the finally statements makes us not see the main error.

def getQueryOutputSchema(
      query: String, options: JDBCOptions, dialect: JdbcDialect): StructType = {
    val conn: Connection = dialect.createConnectionFactory(options)(-1)
    try {
      val statement = conn.prepareStatement(query)
      try {
        statement.setQueryTimeout(options.queryTimeout)
        val rs = statement.executeQuery()
        try {
          JdbcUtils.getSchema(rs, dialect, alwaysNullable = true,
            isTimestampNTZ = options.preferTimestampNTZ)
        } finally {
          rs.close()
        }
      } finally {
        statement.close()
      }
    } finally {
      conn.close()
    }
  } 

Issue Links

• links to: GitHub Pull Request #45209