Patent ID: 7991798

Claim:
A computer-implemented method, comprising: receiving a first command to change the datatype associated with a first column of a table from a first datatype to a second datatype, wherein the first column is associated with a first column name; in response to the first command to change the datatype, (1) creating a second column of the table for storing items associated with the second datatype, and (2) associating said second column with said first column name, without having migrated all values residing in the first column from said first column to said second column; without having migrated all values residing in the first column from said first column to said second column: storing a new value in said second column; in response to a second command that requests a value by referring to the first column name, retrieving said new value from the second column; in response to a third command that requests a value by referring to the first column name, retrieving a second value from the first column and converting said second value to said second datatype; wherein the method is performed by one or more computing devices.