How to delete data for a period and check for integrity?

Question

Database administration

The database has grown in 5 years to a huge size. What commands to do the cleaning of data, leaving the last year? What commands to check for integrity and optimize?

Answer 1

What commands should be used to trunk data and leave data for the last year?

If there are partitions, delete the partitions
https://docs.microsoft.com/ru-ru/sql/t-sql/stateme...

TRUNCATE TABLE PartitionTable1   
WITH (PARTITIONS (2, 4, 6 TO 8));  
GO

If there are no partitions and there is little data, it is easy to delete . If there is a lot of data, make a task in SQL Agent. The number of rows to delete is up to you.
DELETE FROM table WHERE date <= %date%
DELETE TOP (1000) FROM table WHERE date <= %date%

What commands to check for integrity and optimize?

Check the integrity and consistency - only manually. The necessity and possibility of deleting your data is determined only by you.
If you need to check if the database is broken, then use the DBCC CHECKDB command
https://docs.microsoft.com/ru-ru/sql/t-sql/databas...
PS Backups and other stuff would be nice