Question on BIGINT conversion exercise Sybase ASE 15.7

Hello,

Currently we are in process of converting production db tables from INT to BIGINT with Sybase ALTER command.

One of the table has 1.5Billion rows which we are unable to convert in one weekend time frame (ran for almost 43 hours then we killed it & restored the DB dumps).

Any other suggestion to convert this table quickly to BIGINT. This table has clustered, unique and non-clustered indexes on it.

I am thinking below solutions: Can you suggest the best way to do this?

1. Create a new column & update it with old value then drop the old column followed by renaming the new column.
2. BCP out the data, truncate the table, alter the table structure with new data types then BCP in the data
3. Partition the table into small tables then alter the table & merge it again.
   

Regards,

Nagu