SYCYUY Transaction Processing in Firm Real-Time Database Systems

\l,ili\. rc&t;,iiiir~ dat,al);t SII(:(:~SS of the enterprise. A secure real-time (till ill)ilSC' svst,niii hits to simultaneously satisfy two requireIII(YII.~ guarant,ee data security and minimize the number 111’ ttlihs(s(l transnc.t,ion deadlines. We investigate here the 1”” ~HXIMI~Y uuplications, in terms of missed deadlines, of g:l~;mt,~&g; sec,urity in a real-time database system. In 1)il,rtl4ar. wc f0c.u~ on the concurrency control aspects of 1 IIIC Ihkll(’ ( )III. ulalll c,orlt.ril,ut,iolis are the following: First, we idenI II \. \vllic.ll i~uluug t,ht: previously proposed real-time concurKI’~~(‘v (control l)rot,ocols a.re capable of providing protection ,I~:.IIII>I IHJI II tll1,cnc.l and mdirect, (covert. channels) means of tltl;lllthc~rlzr~tI H(‘(YM t,o data Second, using a detailed simuIat,lou model of a firm-deadline real-time database system, wt. profile the real-time performance of a representative set I )I tI143~ h(‘(.\ir(’ (‘oii(‘urrcl!c~ control prot,ocols. Our exper11u~11t.h show that, a priorltlzed optimistic concurrency cont.1.01 protoc.ol. OPT-WAIT, provides the best overall perfor1‘1rlll( 0 Thirtl. WI: propose and evaluate a novel dual appt’oa4 r.o secure transact,ion concurrency control that alIo\v~ th(l r(‘ilt-t.imtb database system to simultaneously use ~l~ff’c*~~c~r~t (‘oncurreu(~y control mechanisms for guaranteeing Y(Y III’II v ,III(I for improving real-time performance. By appropriately choosing these different mechanisms, we have IHY’II a t)l(* 1.0 tl(Ggn hylbr~d concurrency control algorithms I 11~11 I~~~I\‘I(Iv (~VVII I)c:t,t.c:r performance than OPT-WAIT.