Multilevel Data Clustering for Spatial Join Processing

Thc spatial join is a cuminon spalid query typc that requires n high processing cost due lo thc largc volume of spatial detil and the computntion-iiitcnsivc spatial opcrntions [ I , 12, 13, 141. A spalial join consists in testing cvcry two possible pairs of objects hdoinging to two spatia? daln sets against n spalial predicatc [ 1 I ] . This prcdicnte might be flveriiip, cross, wilhiit distarice, crcljuceiit io, contuA, intersect etc. Spatial join queries usually access n large nnmhcr of spatial [lata. Exaniples o t such querics arc ‘ ‘ j inr i in~ all buildings that are ladjt-icuitt to roarls”[l2] and ‘5irirlkg 011 the F e s i d e r t t i o i p ~ ~ ~ ~ r i i e s w i h clistunce o f 1 knt of a c h e w Kowloon, Hong Kong jia @ cs. cityu. e h . hk