[TAJO-684] Add functions about time

• Type: Task
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 0.8.0, 0.9.0
• Component/s: Function/UDF
• Labels: patch
• Assignee: Alvin Henrick
• Reporter: Jihoon Son
• Created: 09/Mar/14 07:11
• Updated: 26/Mar/14 06:49
• Resolved: 26/Mar/14 06:02

Description

Functions about time such as utc_usec_to_second(), utc_usec_to_minute(), utc_usec_to_hour(), utc_usec_to_day(), utc_usec_to_week(), utc_usec_to_year() are popularly used in many applications.
These functions are useful when we group data with tome intervals.
For example, utc_usec_to_day() works as follows.

tajo> select utc_usec_to_day(1274259481071200);
1274227200000000

We need to provide these functions by default.