1. A computer-implemented method of reducing database downtime for online applications, the method comprising: providing a source database and a target database; copying data, using one or more processors associated with one or more servers, from the source database to the target database to create a mirrored set of data; limiting access to one or more designated tables in the target database; redirecting general traffic from the source database to the target database, wherein the redirection occurs for a duration of a maintenance period; capturing, using the one or more processors associated with the one or more servers, data modifications occurring in the target database during the maintenance period; replicating, using the one or more processors associated with the one or more servers, the data modifications into the source database; and redirecting general traffic from the target database to the source database.