1. A system for supporting transient partition consistency in a distributed data grid, comprising: a storage data structure on a cluster node in the distributed data grid, wherein the storage data structure stores data in one or more partitions on the cluster node; and an index data structure for the data stored in the one or more partitions, wherein the index data structure contains a plurality of indexes, wherein each index supports at least one data grid operation on the one or more partitions; wherein the distributed data grid operates to determine whether an index in the index data structure is consistent with the one or more partitions by checking a partition version number of each said partition; and update the index in the index data structure to maintain consistency between the index data structure and the storage data structure to support the at least one data grid operation on the one or more partitions.