[DRILL-4939] to_date function returns incorrect result

• Type: Bug
• Status: Resolved
• Priority: Critical
• Resolution: Not A Problem
• Affects Version/s: 1.9.0
• Fix Version/s: 1.16.0
• Component/s: Execution - Data Types
• Assignee: Unassigned
• Reporter: Khurram Faraaz
• Created: 10/Oct/16 14:25
• Updated: 03/Mar/19 13:07
• Resolved: 03/Mar/19 13:07

Description

to_date function returns wrong result

correct results from Postgres

postgres=# values(to_date('2016-09-22','yyyy-mm-dd'));
  column1
------------
 2016-09-22
(1 row)

wrong results returned by Drill 1.9.0 git commit id: 4edabe7a

: jdbc:drill:schema=dfs.tmp> values(to_date('2016-09-22','yyyy-mm-dd'));
+-------------+
|   EXPR$0    |
+-------------+
| 2016-01-22  |
+-------------+
1 row selected (0.125 seconds)

Postgres 9.3 returns true for below query whereas drill 1.9.0 returns false.

0: jdbc:drill:schema=dfs.tmp> select (res1 = to_date('2016-09-22','yyyy-mm-dd')) res2
. . . . . . . . . . . . . . > from
. . . . . . . . . . . . . . > (
. . . . . . . . . . . . . . >     select (case when (false) then null else cast('2016/09/22' as date) end) res1
. . . . . . . . . . . . . . >     from (values(1)) foo
. . . . . . . . . . . . . . > ) foobar;
+--------+
|  res2  |
+--------+
| false  |
+--------+
1 row selected (0.146 seconds)

postgres=# select (res1 = to_date('2016/09/22','yyyy-mm-dd')) res2
postgres-# from
postgres-# (
postgres(#     select (case when (false) then null else cast('2016/09/22' as date) end) res1
postgres(#     from (values(1)) foo
postgres(# ) foobar;
 res2
------
 t
(1 row)

Postgres 9.3 returns an error for below query, where as Drill git commit ID: 4edabe7a returns some results.
This looks like it has to do with the to_date function in drill.

0: jdbc:drill:schema=dfs.tmp> select (res1 = to_date(2016/09/22)) res2
. . . . . . . . . . . . . . > from
. . . . . . . . . . . . . . > (
. . . . . . . . . . . . . . >     select (case when (false) then null else cast('2016/09/22' as date) end) res1
. . . . . . . . . . . . . . >     from (values(1)) foo
. . . . . . . . . . . . . . > ) foobar;
+--------+
|  res2  |
+--------+
| false  |
+--------+
1 row selected (0.166 seconds)

Issue Links

• relates to: DRILL-4864 Add ANSI format for date/time functions