An Overview of The System Software of A Parallel Relational Database Machine GRACE

I’llis paper olll.lincs the system soflware of a parallel reI:ll.iollaI dnl.nhase machine GRACE. and describes its execul.inn and conlrol of rclnl.ional operalions based. on the data .s/rnom o~i.enlnrl processing. The system software is organized in a hicrnrchy. and the execulion of a relalional operation and il.s opcmnd tlnl.;~ are encapsulated and controlled in lhe’ rOrln Or htk. The dala stream conLol ~olocol bclween n~odulcs in a lnsk makes lasks autonomdus objecls. The sysl.cm sorl.warc we propose eliminales lhe grealer p’arl ol possihlc conI.roI ovcrhcods firs1 by adopting Che task-level grnnuInri1.y lnr l.hc execuI.ion and control, lhen by execuling Ihe operation along 1.11~ flow of operand dala. The former rctluces Ihc control overhead for enabling the execution of a rcl;rl.ionnl operal.ion, while the laller hides the execul.ion hchind I.IIc I/O’s or da1.a I.rjnsler. 11s preliminary implemenI.rll.ion on lhc soflwarc simulalor of GRACE is also reporled. In nddil.ion. the novel virtual space management algorithm is proposed, which enables us lo handle a iarge data stream qui1.c cllicienl.ly.