[DRILL-5334] Questionable code in the TimeVector class

• Type: Bug
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 1.9.0
• Assignee: Unassigned
• Reporter: Paul Rogers
• Created: 08/Mar/17 05:52
• Updated: 11/Oct/18 09:45

Description

The TimeVector class, which holds Time data, should hold a simple local time with no associated date or time zone. (A local time cannot be converted to UTC without a date since the conversion depends on when daylight savings is in effect.)

But, the implementation of TimeVector uses the following very questionable code:

    @Override
    public DateTime getObject(int index) {
        org.joda.time.DateTime time = new org.joda.time.DateTime(get(index), org.joda.time.DateTimeZone.UTC);
        time = time.withZoneRetainFields(org.joda.time.DateTimeZone.getDefault());
        return time;
    }

That is, we convert a date-less, local time into a Joda UTC DateTime object, then reset the time zone to local time. This is abusing the Joda library and is the very kind of fun & games that Joda was designed to prevent.

The conversion of a time into Joda should use the LocalTime class.

In fact, according to Oracle, the following is the mapping from ANSI SQL date/time types to Java 8 (and thus Joda) classes:

ANSI SQL	Java SE 8
DATE	LocalDate
TIME	LocalTime
TIMESTAMP	LocalDateTime
TIME WITH TIMEZONE	OffsetTime
TIMESTAMP WITH TIMEZONE	OffsetDateTime

Issue Links

• is related to: DRILL-5332 DateVector support uses questionable conversions to a time
• relates to: DRILL-4060 CTAS to csv or json files gives incorrect time values
• relates to: DRILL-6242 Output format for nested date, time, timestamp values in an object hierarchy