1. A method for identification of ribosomal deoxyribonucleic acid (rDNA) sequences from a sample containing a plurality of unknown DNA sequences, the method comprising: selecting, based on a composition based analysis, one or more target clusters corresponding to a query sequence, wherein the one or more target clusters are selected from a plurality of reference clusters; determining a proportion of probable rDNA clusters from the one or more target clusters; and identifying the query sequence as an rDNA sequence, based on the proportion of probable rDNA clusters.