Long story short. I have a table with more than 10millions rows with a datetime field. WE can change that to DATE ( because date uses 3bytes, and datetime 8).
I thought if I:
alter table table1 alter column column1 date
I would reclaim more than half the space allocated.
but doing some tests, I can't see any space being reclaimed.
exec sp_spaceused datas2 datas 110000 8136 KB 8080 KB 8 KB 48 KB --with datetime datas 110000 8136 KB 8080 KB 8 KB 48 KB --with date
both with 8080KB.
but then if I create a new table, with the same ammount of data, but with DATE since the beggining, I can see a good storage improvement:
datas2 110000 4744 KB 4688 KB 8 KB 48 KB
Now my table has 4688 KB.
How can I reclaim that space on a table that would be altered from datetime to date?