STDDEV_SAMP Function Examples | Teradata Vantage - 17.10 - Example: Using STDDEV_SAMP with Time Series - Advanced SQL Engine - Teradata Database

Teradata Vantageā„¢ - Time Series Tables and Operations

Product
Advanced SQL Engine
Teradata Database
Release Number
17.10
Release Date
July 2021
Content Type
Programming Reference
Publication ID
B035-1208-171K
Language
English (United States)

For a PTI table:

SELECT $TD_TIMECODE_RANGE, $TD_GROUP_BY_TIME, BUOYID, STDDEV_SAMP(CAST(TEMPERATURE AS REAL))
FROM OCEAN_BUOYS
WHERE TD_TIMECODE BETWEEN TIMESTAMP '2014-01-06 08:00:00' AND TIMESTAMP '2014-01-06 10:30:00'
GROUP BY TIME (MINUTES(10) AND BUOYID)
ORDER BY 3,2,1;

For a non-PTI table:

SELECT $TD_TIMECODE_RANGE, $TD_GROUP_BY_TIME, BUOYID, STDDEV_SAMP(CAST(TEMPERATURE AS REAL))
FROM OCEAN_BUOYS_NONPTI
WHERE TIMECODE BETWEEN TIMESTAMP '2014-01-06 08:00:00' AND TIMESTAMP '2014-01-06 10:30:00'
GROUP BY TIME (MINUTES(10) AND BUOYID)
USING TIMECODE(TIMECODE)
ORDER BY 3,2,1;

Result:

The results of both queries are identical so only one result set is shown.
TIMECODE_RANGE GROUP BY TIME (MINUTES(10)) BUOYID Stddev_Samp (TEMPERATURE)
('2014-01-06 10:10:00.000000+00:00', '2014-01-06 10:20:00.000000+00:00') 14 44 ?
('2014-01-06 10:00:00.000000+00:00', '2014-01-06 10:10:00.000000+00:00') 13 44 5.75808610178378E 000
('2014-01-06 09:00:00.000000+00:00', '2014-01-06 09:10:00.000000+00:00') 7 1 3.93700393700591E 000
('2014-01-06 08:10:00.000000+00:00', '2014-01-06 08:20:00.000000+00:00') 2 0 6.36396103067893E 001
('2014-01-06 08:00:00.000000+00:00', '2014-01-06 08:10:00.000000+00:00') 1 0 6.29325035256027E 001

Example: Filtering Out NULL Results with the HAVING Clause

For a PTI table:

SELECT $TD_TIMECODE_RANGE, $TD_GROUP_BY_TIME, BUOYID, STDDEV_SAMP(CAST(TEMPERATURE AS REAL))
FROM OCEAN_BUOYS
WHERE TD_TIMECODE BETWEEN TIMESTAMP '2014-01-06 08:00:00' AND TIMESTAMP '2014-01-06 10:30:00'
GROUP BY TIME (MINUTES(10) AND BUOYID)
HAVING STDDEV_SAMP(TEMPERATURE) IS NOT NULL
ORDER BY 3,2,1;

For a non-PTI table:

SELECT $TD_TIMECODE_RANGE, $TD_GROUP_BY_TIME, BUOYID, STDDEV_SAMP(CAST(TEMPERATURE AS REAL))
FROM OCEAN_BUOYS_NONPTI
WHERE TIMECODE BETWEEN TIMESTAMP '2014-01-06 08:00:00' AND TIMESTAMP '2014-01-06 10:30:00'
GROUP BY TIME (MINUTES(10) AND BUOYID)
USING TIMECODE(TIMECODE)
HAVING STDDEV_SAMP(TEMPERATURE) IS NOT NULL
ORDER BY 3,2,1;

Result:

The results of both queries are identical so only one result set is shown.
TIMECODE_RANGE GROUP BY TIME (MINUTES(10)) BUOYID Stddev_Samp (TEMPERATURE)
('2014-01-06 08:00:00.000000+00:00', '2014-01-06 08:10:00.000000+00:00') 1 0 6.29325035256027E 001
('2014-01-06 08:10:00.000000+00:00', '2014-01-06 08:20:00.000000+00:00') 2 0 6.36396103067893E 001
('2014-01-06 09:00:00.000000+00:00', '2014-01-06 09:10:00.000000+00:00') 7 1 3.93700393700591E 000
('2014-01-06 10:00:00.000000+00:00', '2014-01-06 10:10:00.000000+00:00') 13 44 5.75808610178378E 000