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EXTRACT (legacy)

You are looking at legacy documentation for Firebolt’s deprecated date and timestamp type functions. New types were introduced in DB version 3.19 under the names PGDATE and TIMESTAMPNTZ, and made generally available in DB version 3.22.

If you worked with Firebolt before DB version 3.22, you might still be using the legacy date and timestamp types. Determine which types you are using by executing the query SELECT EXTRACT(CENTURY FROM DATE '2023-03-16');. If this query returns an error, you are still using the legacy date and timestamp types and can continue with this documentation, or find instructions to use the new types here. If this query returns a result, you are already using the redesigned date and timestamp types and can use the EXTRACT function instead.

Retrieves the time unit, such as year or hour, from a DATE, TIMESTAMP, or TIMESTAMPTZ value.

Syntax 

EXTRACT(<time_unit> FROM <expression>)

Parameters

Parameter Description Supported input types
<time_unit> The time unit to extract from the expression. microseconds, milliseconds, second, minute, hour, day, week, month, quarter, year, decade, century, millennium (unquoted)
<expression> The expression from which the time unit is extracted. DATE, TIMESTAMP, TIMESTAMPTZ

TIMESTAMPTZ values are converted from Unix time to local time according to the session’s time_zone setting before extracting the time_unit. The set of allowed time_unit values depends on the data type of <expression>. Furthermore, the return type depends on the time_unit.

Time Units

Unit Description Supported input types Return type Example
century Extract the century. The first century starts on 0001-01-01 and ends on 0100-12-31 (inclusive). DATE, TIMESTAMP, TIMESTAMPTZ INTEGER SELECT EXTRACT(century FROM TIMESTAMP '0100-12-31'); --> 1
day Extract the day (of the month) field. DATE, TIMESTAMP, TIMESTAMPTZ INTEGER SELECT EXTRACT(day FROM DATE '2001-02-16'); --> 16
decade Extract the year field divided by 10. DATE, TIMESTAMP, TIMESTAMPTZ INTEGER SELECT EXTRACT(decade FROM DATE '0009-12-31'); --> 0
dow Extract the day of the week as Sunday (0) to Saturday (6). DATE, TIMESTAMP, TIMESTAMPTZ INTEGER SELECT EXTRACT(dow FROM DATE '2022-10-13'); --> 4
doy Extract the day of the year (1–365/366). DATE, TIMESTAMP, TIMESTAMPTZ INTEGER SELECT EXTRACT(doy FROM DATE '1972-02-29'); --> 60
epoch For TIMESTAMPTZ, extract the number of seconds since 1970-01-01 00:00:00 UTC. For TIMESTAMP, extract the number of seconds since 1970-01-01 00:00:00 independent of a time zone. DATE expressions are implicitly converted to TIMESTAMP. DATE, TIMESTAMP, TIMESTAMPTZ DECIMAL(38, 6) SELECT EXTRACT(epoch FROM TIMESTAMP '2001-02-16 20:38:40.12'); --> 982355920.120000
hour Extract the hour field (0–23). TIMESTAMP, TIMESTAMPTZ INTEGER SELECT EXTRACT(hour FROM TIMESTAMP '2001-02-16 20:38:40.12'); --> 20
isodow Extract the day of the week as Monday (1) to Sunday (7). DATE, TIMESTAMP, TIMESTAMPTZ INTEGER SELECT EXTRACT(isodow FROM DATE '2022-10-13'); --> 4
isoyear Extract the ISO 8601 week-numbering year that the date falls in. Each ISO 8601 week-numbering year begins with the Monday of the week containing the 4th of January; so in early January or late December the ISO year may be different from the Gregorian year. DATE, TIMESTAMP, TIMESTAMPTZ INTEGER SELECT EXTRACT(isoyear FROM DATE '2006-01-01'); --> 2005
microseconds Extract the seconds field, including fractional parts, multiplied by 1,000,000. TIMESTAMP, TIMESTAMPTZ INTEGER SELECT EXTRACT(microseconds FROM TIMESTAMP '2001-02-16 20:38:40.12'); --> 40120000
millennium Extract the millennium. The third millennium started on 2001-01-01. DATE, TIMESTAMP, TIMESTAMPTZ INTEGER SELECT EXTRACT(millennium FROM TIMESTAMP '1000-12-31 23:59:59.999999'); --> 1
milliseconds Extract the seconds field, including fractional parts, multiplied by 1,000. TIMESTAMP, TIMESTAMPTZ DECIMAL(8, 3) SELECT EXTRACT(milliseconds FROM TIMESTAMP '2001-02-16 20:38:40.12'); --> 40120.000
minute Extract the minutes field (0–59). TIMESTAMP, TIMESTAMPTZ INTEGER SELECT EXTRACT(minute FROM TIMESTAMP '1000-12-31 23:42:59'); --> 42
month Extract the number of the month within the year (1–12). DATE, TIMESTAMP, TIMESTAMPTZ INTEGER SELECT EXTRACT(month FROM DATE '1000-12-31'); --> 12
quarter Extract the quarter of the year (1–4) that the date is in:
[01, 03] -> 1
[04, 06] -> 2
[07, 09] -> 3
[10, 12] -> 4		 DATE, TIMESTAMP, TIMESTAMPTZ INTEGER SELECT EXTRACT(quarter FROM DATE '1000-10-31'); --> 4
second Extract the second’s field, including fractional parts. TIMESTAMP, TIMESTAMPTZ DECIMAL(8, 6) SELECT EXTRACT(second FROM TIMESTAMP '2001-02-16 20:38:40.12'); --> 40.120000
timezone Extract the time zone offset from UTC, measured in seconds, with a positive sign for zones east of Greenwich. TIMESTAMPTZ INTEGER SELECT EXTRACT(timezone FROM TIMESTAMPTZ '2022-11-29 13:58:23 Europe/Berlin'); --> -28800 (assumes set time zone is ‘US/Pacific’)
timezone_hour Extract the hour component of the time zone offset. TIMESTAMPTZ INTEGER SELECT EXTRACT(timezone_hour FROM TIMESTAMPTZ '2022-11-29 13:58:23 Europe/Berlin'); --> -8 (assumes set time zone is ‘US/Pacific’)
timezone_minute Extract the minute component of the time zone offset. TIMESTAMPTZ INTEGER SELECT EXTRACT(timezone_minute FROM TIMESTAMPTZ '2022-11-29 13:58:23 Europe/Berlin'); --> 0 (assumes set time zone is ‘US/Pacific’)
week Extract the number of the ISO 8601 week-numbering week of the year. By definition, ISO weeks start on Mondays and the first week of a year contains January 4 of that year. It is possible for early-January dates to be part of the 52nd or 53rd week of the previous year, and for late-December dates to be part of the first week of the next year. DATE, TIMESTAMP, TIMESTAMPTZ. INTEGER SELECT EXTRACT(week FROM DATE '2005-01-01'); --> 53
SELECT EXTRACT(week from DATE '2006-01-01'); --> 52
year Extract the year field. DATE, TIMESTAMP, TIMESTAMPTZ INTEGER SELECT EXTRACT(year FROM TIMESTAMP '2001-02-16'); --> 2001

Remarks

The EXTRACT function can be used in the PARTITION BY clause of CREATE TABLE commands.

CREATE DIMENSION TABLE test (
  d DATE,
  t TIMESTAMP
)
PARTITION BY EXTRACT(month FROM d), EXTRACT(hour FROM t);