For the sake of demonstration, let's say I try to call unix_timestamp('2014-10-10 10:13:00') in both Hive and Impala. I get two different timestamps:
- Hive: 1412928780
- Impala: 1412935980
Now if I try to look in a third (standard) place what these two timestamps correspond to, it seems to me like Hive is right. I looked in MySQL:
|Hive 1412928780||Impala 1412935980|
|2014-10-10 10:13:00||2014-10-10 12:13:00|
Interestingly, all these tests have been run in the same timezone (Europe/Amsterdam), which is 2 hours behind UTC time. It therefore feels as if Hive assumes the time string I give is in my Timezone, while Impala assumes that string is in the UTC Timezone.
It would be nice if Impala would align its behavior with MySQL and Hive.