Joined: 23 Nov 2006 Posts: 19270 Location: Inside the Matrix
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What dabatase are you using?
You won't like this answer, but to change the length, go to the meta-data, make the change and catalog the new definition. This is done by the dba(s) at most places, not the application developers? Also, all external references to the definition will need to be considered (i.e. other systems that use all or part of the data).
The change to the definition of the table has no relationship to the volume of the data in the table.