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How to find the oldest record in a table?
A common query that crops up in web apps is finding the oldest or the most recent record in a single table. This is straightforward in SQL. You can even write the relevant part of the query without knowing anything about the table (other than the fact that it has a timestamp column called created_at ):
Where to find records with the most recent or oldest dates?
Find the most recent or earliest date Last Name First Name Address City Hire Date Price Julian Calle Smith 2 Mexico City 05-Jan-2002 Hughes Christine 3122 75th St. S. Seattle 23-Apr-1999 Riley Steve 67 Big St. Tampa 14-Oct-2004 Birkby Dana 2 Nosey Pkwy Portland 29-Mar-1997
How to find the oldest order in a group?
A small one if you are displaying the latest orders to the admins of your application (they see two orders for one user). A larger one if you are doing something user-facing. In this situation you’d really just want to pick one of the two and adding a DISTINCT clause on user_id in the above example would do just that.
How to manage data in the temporal history table?
The following four approaches for managing historical data in the temporal history table are available: With each of these approaches, the logic for migrating or cleaning history data is based on the column that corresponds to end of period in the current table.
What should be included in the default history table?
The default history table created by the system contains a clustered index that includes the SysEndTime and SysStartTime columns, which is optimal for partitioning, inserting new history data, and typical temporal querying. For more information, see Temporal Tables. A sliding window approach has two sets of tasks that you need to perform:
How to keep the size of the history table constant?
With table partitioning, you can implement a sliding window approach to move out oldest portion of the historical data from the history table and keep the size of the retained part constant in terms of age – maintaining data in the history table equal to required retention period.