Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for updating data stored within the
database. In some implementations, actions include determining a
cut-off date, defining a first group of data within a first table based on the
cut-off date, defining a second group of data within the first table based on the
cut-off date, providing the second group of data in a second table, converting the first group of data from a first
data structure to a second
data structure to provide converted first data within the first table, making the converted first data available for access over a network, converting the second group of data from the first
data structure to the second data structure to provide converted second data in the second table, and making the converted second data available for access over the network.