Do you need a date dimension?
Date Dimension is not a big dimension as it would be only ~3650 records for 10 years, or even ~36500 rows for 100 years (and you might never want to go beyond that). Date Dimension will be normally loaded once, and used many times after it. So it shouldn’t be part of your every night ETL or data load process.
Why we use date dimension?
A date dimension is an essential table in a data model that allows us to analyze performance more effectively across different time periods. It should be included in every dimensional model that contains a date or requires date intelligence as part of the analysis.
Which is an example of a time dimension?
Most of the analysis by date and time are in that category, as an example; year to date, quarter to date, month to date, same period last year calculations and etc. These calculations they all have one dimension in common; date/time dimension.
Do You need A Date dimension for a year?
Depends on the period used in the business you can define start and end of the date dimension. For example your date dimension can start from 1st of Jan 1980 to 31st of December of 2030. For every year normally you will have 365 records (one record per year), except leap years with 366 records.
When to use date dimension in a column?
Columns will be normally all descriptive information about date, such as Date itself, year, month, quarter, half year, day of month, day of year…. Date Dimension will be normally loaded once, and used many times after it. So it shouldn’t be part of your every night ETL or data load process. Why Date Dimension?
Is there a time dimension for every second?
One cannot build a time dimension with every minute second of every day represented. There are more than 31 million seconds in a year! We want to preserve the powerful calendar date dimension and simultaneously support precise querying down to the minute or second.