1. A computer implemented database management system for in-database clustering, comprising: a memory; a first data table and a second data table stored in the memory, each data table including a plurality of rows of data; means for building a clustering model using the first data table using a portion of the first data table, wherein the portion of the first data table is selected by active sampling of the first data table, wherein active sampling includes categorizing data in the first data table into a first category that is not partitioned further and a second category that is partitioned further; and means for applying the clustering model using the second data table to generate and store, in the memory, apply output data; wherein the building includes determining a splitting point for active partitions by examining separately groups of numeric and categorical attributes and selecting a splitting plane, the examining of the numeric attributes comprising identifying a bin of low density having a first bin of high density on a first side and a second bin of high density on a second side and the examining of the categorical attribute comprising identifying the two largest bins.