Example: FILL with Previous Timebucket Value - Analytics Database - Teradata Vantage

Use the FILL(PREVIOUS) or FILL(PREV) clause to replace missing values with the previous timebucket value for timebuckets with missing values.

The example shows the results of the query when the FILL clause is used with PREVIOUS/PREV:

SELECT $TD_TIMECODE_RANGE, $TD_GROUP_BY_TIME, BUOYID, AVG(TEMPERATURE)
FROM OCEAN_BUOYS
WHERE TD_TIMECODE BETWEEN TIMESTAMP '2014-01-06 09:45:00' AND TIMESTAMP '2014-01-06 11:45:00'
AND BUOYID=44
GROUP BY TIME (MINUTES(15) AND BUOYID) FILL(PREVIOUS)
ORDER BY 2,3;

SELECT $TD_TIMECODE_RANGE, $TD_GROUP_BY_TIME, BUOYID, AVG(TEMPERATURE)
FROM OCEAN_BUOYS
WHERE TD_TIMECODE BETWEEN TIMESTAMP '2014-01-06 09:45:00' AND TIMESTAMP '2014-01-06 11:45:00'
AND BUOYID=44
GROUP BY TIME (MINUTES(15) AND BUOYID) FILL(PREV)
ORDER BY 2,3;

Result: All timebuckets are included as part of the result set. The missing value for timebucket #1 is null because there is no previous timebucket from which to infer the value. The missing value for timebucket #3 is set to the value of its immediate non-missing predecessor (timebucket #2) resulting in a value of 49. The missing values for timebuckets #6, #7 and #8 are all set to their immediate non-missing predecessor (timebucket #5) resulting in a value of 43.