Drill 1.6.0 Release Notes

The following table lists resolved issues in Drill 1.6.0:

Issue	Description
MD-803	LIMIT 0 optimization applies to the ranking and value window functions.
MD-784	LIMIT 0 optimization applies to the Hive UDF xpath_double.
MD-781	LIMIT 0 optimization applies to the TRIM function.
MD-608	Complex data functions FLATTEN and KVGEN no longer return null data when you issue queries through the ODBC driver.
MD-604	EXTRACT function with seconds no longer returns incorrect data when you issue queries through the ODBC driver.
MD-361	Drill honors the Hive skip.header.line.count and skip.footer.line.count table properties and skips header and footer lines when querying Hive tables created with these properties.

The following table lists known issues in Drill 1.6.0:

Issue	Description
MD-851	Pushdown is disabled for columns with TIMESTAMP values which makes these columns case-insensitive. See Limitations.
MD-845	LIMIT 0 optimization does not apply when used in a query with a FULL OUTER JOIN and the planner.enable_mergejoin option is set to true.
MD-817	LIMIT 0 optimization does not apply when a query contains math operations between an interval type and a constant.
MD-802	LIMIT 0 optimization applies to the AVG window function.
MD-794	LIMIT 0 optimization does not apply when the return type is VARBINARY.
MD-787	LIMIT 0 optimization does not apply to the Hive BIN function.
MD-786	LIMIT 0 does not apply to the Hive HEX function.
MD-747	SUM function queries with a decimal argument and LIMIT 0 optimization returns the wrong data types and nullability.
MD-727	If you query a column that does not exist in the records of the queried table, Drill does not return any rows when it should return rows with null values. See Limitations.

(MD-851) Pushdown filtering is disabled on columns with TIMESTAMP values, which results in these columns being case-insensitive. For example, if a JSON table is created with the following JSON records where the “access” columns are not of a particular case:

{"_id":"ID1","name":"Alice","age":"25","access":"2013-10-23 11:11:11","DOB":{"$dateDay":"1988-01-01"},"salary":"50.00"}
{"_id":"ID2","name":"Bob","age":"21","access":"2013-10-23 11:11:11","DOB":{"$dateDay":"1988-01-01"},"salary":"150.00"}
{"_id":"ID3","name":"Frank","age":"32","ACCESS":"2013-10-23 11:11:11","dob":{"$dateDay":"1988-01-01"},"salary":"250.00"}

SELECT * FROM dfs.`/tmp/data/student_db` where access = timestamp '2013-10-23 11:11:11';
+------+----------------------+------+-------------+-----------+---------+
| _id  |        access        | age  |     dob     |   name    | salary  |
+------+----------------------+------+-------------+-----------+---------+
| ID1  | 2013-10-23 11:11:11  | 25   | 1988-01-01  | Alice  | 50.00   |
| ID2  | 2013-10-23 11:11:11  | 21   | 1980-12-12  | Bob     | 150.00  |
| ID3  | 2013-10-23 11:11:11  | 32   | 1970-10-12  | Frank      | 250.00  |
+------+----------------------+------+-------------+-----------+---------+
3 rows selected (0.223 seconds)

In comparison, you can see that a query on the “dob” column in the same table produces only one result because the column does not contain TIMESTAMP values and is therefore case-sensitive:

SELECT * FROM dfs.`/tmp/data/student_db` where dob = date '1988-01-01';
+------+----------------------+------+-------------+-------+---------+
| _id  |        ACCESS        | age  |     dob     | name  | salary  |
+------+----------------------+------+-------------+-------+---------+
| ID3  | 2013-10-23 11:11:11  | 32   | 1988-01-01  | Frank  | 250.00  |
+------+----------------------+------+-------------+-------+---------+
1 row selected (0.359 seconds)

(MD-727) If you query one column that is partially or completely non-existent in the records of the queried table, Drill does not return any rows for the records when it should return the rows with null values. For example, if a JSON table is created from the following JSON records where only one record has a “time” column with a value and the other two records do not have time columns:

{"_id":"student1", "name":"Alice", "street":"123 Ballmer Av", "zipcode":12345, "state":"CA"},
{"_id":"student2", "name":"Bob", "time":"2016-03-08", "street":"1 Infinite Loop", "zipcode":12345, "state":"CA"},
{"_id":"student3", "name":"Frank", "street":"435 Walker Ct", "zipcode":12345, "state":"CA"}

The query returns only one row for the record in which the time column exists with a value instead of returning three rows with two rows having null values in the column.

SELECT `time` FROM dfs.`/user/root/students`;
+-----------+
| time      |
+-----------+
| 2016-03-08|
+-----------+

In comparison, if you query all of the columns in the table, you can see that the query returns all records and includes null values for records missing a time column.

SELECT * FROM dfs.`/user/root/students`;
+-----------+--------+--------+------------------+----------+-------------+
|    _id    |  name  | state  |      street      | zipcode  |    time     |
+-----------+--------+--------+------------------+----------+-------------+
| student1  | Alice  | CA     | 123 Ballmer Av   | 12345.0  | null        |
| student2  | Bob    | CA     | 1 Infinite Loop  | 12345.0  | 2016-03-08  |
| student3  | Frank  | CA     | 435 Walker Ct    | 12345.0  | null        |
+-----------+--------+--------+------------------+----------+-------------+
3 rows selected (0.314 seconds)