0 - 3 of 3 tags for modify

I am Altering the table for addition of new columns. And tables is having more than 1 billion records.
Please let us know is it standard to alter the table with more than one billion records or not. Also guide us in best practise to alter the table with data.

Hi everyone
I've created a table and I want to modify the datatype to one field from Char(4) to Char(5) but it is not possible....I tried to rename the column using the following statement and it was executed OK.

Hi All,
I have an existing table in TERADATA and it has a field named log_dttm defined as timestamp.
I want to change the column data type to varchar(30).
"alter table modify" failed to convert.
 ALTER TABLE Failed. 3558:  Cannot alter the specified attribute(s) for log_dttm.