Description
Given that input value is "YYYY-MM-DD HH:MM:SS.nnn" type of TIMESTAMP (UNSIGNED_TIMESTAMP, DATE, TIME etc)
When applying TRUNC|ROUND|FLOOR|CEIL with DAY|HOUR|MINUTE|SECOND|MILLISECOND
Than result should be "YYYY-MM-DD HH:MM:SS.nnn"
But "YYYY-MM-DD" is returned instead.
Basically when I do TRUNC on timestamp I would expect it to be timestamp with relevant parts truncated so for example I can GROUP BY on TRUNC (timestamp,'HOUR') and have my hourly aggregation.
Here is test queries with cast(current_date() AS timestamp).
SELECT dt ,TRUNC(dt,'DAY') AS trunc_day_from_dt ,TRUNC(dt,'HOUR') AS trunc_hour_from_dt ,TRUNC(dt,'MINUTE') AS trunc_min_from_dt ,TRUNC(dt,'SECOND') AS trunc_sec_from_dt ,TRUNC(dt,'MILLISECOND') AS trunc_mil_from_dt FROM (SELECT current_date() AS d, cast(current_date() AS timestamp) AS dt, TO_NUMBER(current_date()) e FROM system.catalog LIMIT 1) t; +------------------------------------------+---------------------+---------------------+---------------------+---------------------+---------------------+ | TO_TIMESTAMP('2015-03-08 09:09:11.665') | TRUNC_DAY_FROM_DT | TRUNC_HOUR_FROM_DT | TRUNC_MIN_FROM_DT | TRUNC_SEC_FROM_DT | TRUNC_MIL_FROM_DT | +------------------------------------------+---------------------+---------------------+---------------------+---------------------+---------------------+ | 2015-03-08 09:09:11.665 | 2015-03-08 | 2015-03-08 | 2015-03-08 | 2015-03-08 | 2015-03-08 | +------------------------------------------+---------------------+---------------------+---------------------+---------------------+---------------------+ 1 row selected (0.066 seconds) SELECT dt ,ROUND(dt,'DAY') AS round_day_from_d ,ROUND(dt,'HOUR') AS round_hour_from_d ,ROUND(dt,'MINUTE') AS round_min_from_d ,ROUND(dt,'SECOND') AS round_sec_from_d ,ROUND(dt,'MILLISECOND') AS round_mil_from_d FROM (SELECT current_date() AS d, cast(current_date() AS timestamp) AS dt, TO_NUMBER(current_date()) e FROM system.catalog LIMIT 1) t; +------------------------------------------+---------------------+---------------------+---------------------+---------------------+------------------------------------------+ | TO_TIMESTAMP('2015-03-08 09:09:11.782') | ROUND_DAY_FROM_D | ROUND_HOUR_FROM_D | ROUND_MIN_FROM_D | ROUND_SEC_FROM_D | ROUND_MIL_FROM_D | +------------------------------------------+---------------------+---------------------+---------------------+---------------------+------------------------------------------+ | 2015-03-08 09:09:11.782 | 2015-03-08 | 2015-03-08 | 2015-03-08 | 2015-03-08 | 2015-03-08 09:09:11.782 | +------------------------------------------+---------------------+---------------------+---------------------+---------------------+------------------------------------------+ 1 row selected (0.06 seconds) SELECT dt ,FLOOR(dt,'DAY') AS floor_day_from_dt ,FLOOR(dt,'HOUR') AS floor_hour_from_dt ,FLOOR(dt,'MINUTE') AS floor_min_from_dt ,FLOOR(dt,'SECOND') AS floor_sec_from_dt ,FLOOR(dt,'MILLISECOND') AS floor_mil_from_dt FROM (SELECT current_date() AS d, cast(current_date() AS timestamp) AS dt, TO_NUMBER(current_date()) e FROM system.catalog LIMIT 1) t; +------------------------------------------+---------------------+---------------------+---------------------+---------------------+---------------------+ | TO_TIMESTAMP('2015-03-08 09:09:11.895') | FLOOR_DAY_FROM_DT | FLOOR_HOUR_FROM_DT | FLOOR_MIN_FROM_DT | FLOOR_SEC_FROM_DT | FLOOR_MIL_FROM_DT | +------------------------------------------+---------------------+---------------------+---------------------+---------------------+---------------------+ | 2015-03-08 09:09:11.895 | 2015-03-08 | 2015-03-08 | 2015-03-08 | 2015-03-08 | 2015-03-08 | +------------------------------------------+---------------------+---------------------+---------------------+---------------------+---------------------+ 1 row selected (0.059 seconds) SELECT dt ,CEIL(dt,'DAY') AS ceil_day_from_dt ,CEIL(dt,'HOUR') AS ceil_hour_from_dt ,CEIL(dt,'MINUTE') AS ceil_min_from_dt ,CEIL(dt,'SECOND') AS ceil_sec_from_dt ,CEIL(dt,'MILLISECOND') AS ceil_mil_from_dt FROM (SELECT current_date() AS d, cast(current_date() AS timestamp) AS dt, TO_NUMBER(current_date()) e FROM system.catalog LIMIT 1) t; +------------------------------------------+---------------------+---------------------+---------------------+---------------------+------------------------------------------+ | TO_TIMESTAMP('2015-03-08 09:09:12.009') | CEIL_DAY_FROM_DT | CEIL_HOUR_FROM_DT | CEIL_MIN_FROM_DT | CEIL_SEC_FROM_DT | CEIL_MIL_FROM_DT | +------------------------------------------+---------------------+---------------------+---------------------+---------------------+------------------------------------------+ | 2015-03-08 09:09:12.009 | 2015-03-09 | 2015-03-08 | 2015-03-08 | 2015-03-08 | 2015-03-08 09:09:12.009 | +------------------------------------------+---------------------+---------------------+---------------------+---------------------+------------------------------------------+ 1 row selected (0.061 seconds)