I need to add three columns to a huge table(close to 99 million records). Value in these columns for 99 million existing records will remain as null itself.So no need of any update for 99 million records.There is no column compression of this table.Its ok to add new columns at the end of the table also.
Which is better way to add three columns
a) Alter this table or
b) create back up of table-->create new table with three new columns--> insert data from back up to new table--> drop back up table.
I heard alter will cause performance issue and cause CPU spike?Is that true? If yes why is that so?