Adding Column on Huge Table

[Moin Akther <moindba@xxxxxxxxxxx>]

Dear Experts,

We want to add a column on table size of 1.5TB, we have to perform this activity with minimal downtime. 

What are the best practises to add a column on huge table ?

How much time alter statement will take to add column ?

Any alternate solution other than alter statement to add column ?

Will adding a new column on a huge table generate huge WAL files ?

Thanks and Best Regards,

Akther