Patent ID: 8601474
Filing Date: 2013-12-03
Classification: G06F

Abstract:
1. A method comprising: executing, at a first virtual machine, a query implemented by a first execution plan; in response to a move command that requests a move of the first virtual machine from a first computer to a second computer while the first virtual machine is executing the query implemented by the first execution plan at the first computer, saving an attribute of a resource used by the executing at the first virtual machine to memory at the first computer and saving a driver source used by the executing at the first virtual machine to the memory at the first computer, wherein the driver source comprises a state of partial execution of the first execution plan; and in response to a command that requests starting a second virtual machine at the second computer, determining whether the driver source that comprises the state of the partial execution of the first execution plan exists in memory of the second computer, wherein the driver source comprises an identifier of a most recent row read from each table in a join order of a plurality of tables that implement the query, wherein the driver source comprises identifiers that uniquely identify rows from a source table that are in a result set and that satisfy the query, wherein the driver source comprises identifiers that uniquely identify rows from the source table that have been processed by the executing of the first virtual machine, but have not been added to the result set because those rows do not satisfy the query.