The data warehouse have 2 dimension tables and 1 fact table. 1 dimension table contains datetime data and the other contain the device data. The fact table contains the device incoming data values captured at the field. The data granularity in the fact table is 5 minutes.
I am confused on how time-series is being handled and will appreciate if someone can clarify this. Assuming one row of data coming from the device looks like this:
datetime drive_a drive_b drive_c shaft_a shaft_b shaft_c total_output 02/01/2022 13:05 4.2 3.2 7.4 5.3 8.2 6.4 4563.2
This will be processed and stored into the fact table in the data warehouse.
How do I handle the
datetime column from this incoming data since the
dateKey is not the same format as the
datetime incoming data?
I am thinking that the fact table need another column called
dateTime_raw, but that defeat the purpose of a
dim_datetime table isn't it since my datetime is already in my fact table?
P.S: Sorry if my question is confusing; trying my best to explain since I am not proficient in this field.