Interval Qualifier

Specifies how to interpret and format an interval literal for output, and, optionally, sets precision. Interval qualifiers are composed of one or two units:

unit[p] [ TO unit[p] ]

where:

unit specifies a day-time or year-month subtype.
p specifies precision, an integer between 0 and 6. In general, precision only applies to SECOND units. The default precision for SECOND is 6. For details, see Specifying Interval Precision.

If an interval omits an interval qualifier, the default is DAY TO SECOND(6).

Interval qualifiers are divided into two categories: day-time and year-month, as shown in the tables below.

Day-time interval qualifiers
Qualifier	Description
`DAY`	Unconstrained
`DAY TO HOUR`	Span of days and hours
`DAY TO MINUTE`	Span of days and minutes
`DAY TO SECOND`	Span of days, hours, minutes, seconds, and fractions of a second.
`HOUR`	Hours within days
`HOUR TO MINUTE`	Span of hours and minutes
`HOUR TO SECOND`	Span of hours and seconds
`MINUTE`	Minutes within hours
`MINUTE TO SECOND`	Span of minutes and seconds
`SECOND`	Seconds within minutes Note: The `SECOND` field can have an interval fractional seconds precision, which indicates the number of decimal digits maintained following the decimal point in the `SECONDS` value. When `SECOND` is not the first field, it has a precision of 2 places before the decimal point.

Year-month interval qualifiers
`YEAR`	Unconstrained
`MONTH`	Months within year
`YEAR TO MONTH`	Span of years and months

Note: Vertica also supports INTERVALYM, which is an alias for INTERVAL YEAR TO MONTH. Thus, the following two statements are equivalent:

=> SELECT INTERVALYM '1 2';
 ?column?
------------
 1 year 2 months

=> SELECT INTERVAL '1 2' YEAR TO MONTH;
    ?column?
-----------------
 1 year 2 months
(1 row)

Examples

See Controlling Interval Format.