20. The method of claim 1, wherein the data is stored in a database, further comprising the steps of: reducing a dimensionality of the database and generating dimensionality reduction information associated with the database; and storing the dimensionality reduction information associated with the database; wherein said partitioning step is responsive to said reducing step.
20. The method of claim 1, wherein the data is stored in a database, further comprising the steps of: reducing a dimensionality of the database and generating dimensionality reduction information associated with the database; and storing the dimensionality reduction information associated with the database; wherein said partitioning step is responsive to said reducing step. 22. The method of claim 20, for performing a similarity search, comprising the steps of: reducing the dimensionality of specified data using the dimensionality reduction information associated with the database; finding the cluster to which reduced dimensionality specified data belongs, based on the clustering information; reducing the dimensionality of the reduced dimensionality specified data based on the dimensionality reduction information for an identified cluster; searching for a reduced-dimensionality version of the cluster to which the further reduced dimensionality specified data belongs; retrieving via the multidimensional index, k records most similar to the further reduced dimensionality specified data in the cluster; assessing whether other clusters can contain records closer to the specified data than the farthest of the k records retrieved; searching a closest other cluster to the specified data, in response to said assessing step; and repeating said assessing and searching for all said other clusters.