Incremental Maintenance of Materialized OQL Views - School of ...
Incremental Maintenance of Materialized OQL Views M. Akhtar Ali
Alvaro A.A. Fernandes
Norman W. Paton
Dept. of Computer Science University of Manchester Manchester M13 9PL, UK
Dept. of Computer Science University of Manchester Manchester M13 9PL, UK
Dept. of Computer Science University of Manchester Manchester M13 9PL, UK
[email protected]
[email protected]
[email protected]
ABSTRACT
!#"$&%'(%') *$&+%),-*. 0/ $&0 1 2!"3 4!5$ ,6%)7(! 859': , )/.? %@ *%%# A " 1 B% , 6 %+ C 1 D E . 0/F)1G *!H"$&% ?JIK 1L *M %N $B OP Q %A ,D R%1D Q ,-*!S T , J%U ),% ?B;V ,% %& (GaK& VA% . 0-(#!7$ ,6% )1 GWN2[ . 6%) , ), , L
%6 % [ m F !l% 6 ,4?I ,~! %> D % D /b @ % = . a2[ 5 7 . D6 ,%< K % . *! T ( H(! ,. %N %C %c$&0 $ OD./ b >U %*G > % ?kI ,bA 6(!K %J!b ,. %k 7L6K 6 5$B O ? 2. TECHNICAL BACKGROUND
1.
INTRODUCTION
: "$o!K-( lL 0X/Q%1" 6(D C[ /S!GD(% n *G ,% ?BpqJ(%&D FO *$&b[ 2% , ` # + . 0 hbvx "3 /T b(), %#D S!A @ ),.#Gy\ 0*?z B % *% 'MK0%), 0/m!K %0 D J @ K , )3G 2 () %5 . 0/.M {? ? M\ 6 + 7(),% ` ) . "$x)3'?TpX. %N7Qhbv2%7%@ *%*!l%7
%6 0V (2) *$&)5*$ %%V B .Z , B f / )2 /Fc!G1$k ,6%)m ,. a % ?2%$sG * ,D , % %N6(*"3 `!U D 0 /AD KL*% D ~ H P , 6 H)3 (!)3~"$
Permission to make digital or hard copies of all or part of this work for personal or classroom use is granted without fee provided that copies are not made or distributed for profit or commercial advantage and that copies bear this notice and the full citation on the first page. To copy otherwise, to republish, to post on servers or to redistribute to lists, requires prior specific permission and/or a fee. DOLAP ’2000 Washington, D.C, USA Copyright 2000 ACM 0-89791-88-6/97/05 .. 5.00
%+% > S. !6 %+a %5 J8 / U %%)= ,%A6% !S P m% 6 ,4M% 0-(* 0/P ,%m 1U !mT85;&i5x .M G Z(!FUYg+j G ? -(0 ,H ),6) u 8 /F KU ),6) u 8+d59w>? I , 5{ G q/F$&0 F %J ! ' %2%%6 *! ~ *?H8 C$&P!>U -( %1 b", !r ,sq/K % ?zZ),6K SH%ra 8 K? ,333l,, ,¡3¢..¢£,K¤¥ ¢3¢,K¦G§3¨.¢3©G¢3K¦G.ªrK «Z¬ ¢3¢,K¦G§3¨.¢3¨,3¦ª,.,jG®K,¢¯ª.Z¬ ¢3¢,K¦G§3¨.¢3©G¢3K¦G.ª33..3'¬ °\¬ ,333Q.3¢G«.¢ ,¡3¢..¢±K3¢G«3¢Kj¤¥ ¢3¢,K¦G§3¨.¢3©G¢3K¦G.ªrK «Z¬ ¢3¢,K¦G§3¨.¢3©G¢3K¦G.ª33..3'¬ ..,¢K¦,KG®¦G,¢.²,*«KK,³.3.´¯*«K3³.3. ¦*.µ.,K*«KK3³.3f¶3¶Y..¢f¬°4¬ ,333r*«K3³.3¯,¡,¢..KP,K,G ,¡3¢..¢·«KK,³.3¤Q¥ ¢3¢,K¦G§3¨.¢3¨,3¦ª,.,3.ª¯,33,³f¬ ¢3¢,K¦G§3¨.¢3©,¢²K,K´s3.3.¢K'¬ ..,¢K¦,KG®¦G.3¢G«.¢¯..¢ ¦*.µ.,K.K,¢G«.¢f¶3¶X*«K3³.3.'¬ ¢3¢,K¦G§3¨.¢3 «KK3³33l«(Kª.,f¬ °\¬ ¸&¹[º »¼G½P¾(¿#ÀJÁ'Â(Ã=ÄfÅ[½=Æ1ÇCÈ]É'Ê˽Ã=Â
zZ)6 J2!K %VAa k8+d59me.6 /# G"3 fzZ )6 5(! "K$r!K-(*!76% )a 6 ,= % ?m:2caK 6K ~ `~% % `G *!C. " !$#%#j!m , *!\?VJ %6 0 )@aKU 6D ,M$&
64M " 6(G %B J ) '8+d59Te.6 /.?fUqg5 ! %JAe.6> / . %%) K 3>F % 0/C % AD )7 (G 6%*!FH%N ng+khHI% % `! '?:2%&$ % k , , !4M3 7@+BA % - %V ka .V0%*% u ,? )K? M
CEDGFH ;JI +.+2K w>MZm",G `D 1 ),)C G"3 + 7 ,DWN > %@c (5aU . u ,? )?M + w>Mf(!~ " ,!0 , u ? )K?M 6 > -03ML M4= % *%A1" 6 ,6% /m 6+ Gw>?k:2%k$ f%2 + , !4MK : , > #% 0-( %+0 % + w>? U % ! %V k `!A(!@ " ,!0 , u " 6 ,6% 0/@ 6 b +>a Gw>MK *,+.-0/1.+ 5!K-( %J1%N 6 6K 5L m %6 0 %A > 6 ! u ? )K?M KRA2* -03ZC[8+U > 6DQ+JL28Q4 =P> -03ZNX8 - U > 6 DQ+JL5L w\!++. ( ," D u ,? )K? M VXW w (G*#D 6%*! F [ 7 b %@%N % ?TIK6SF%N 6 6 ,%%N %@ 4 =P> aK %% % u ? )K?M 4 =P> -03ZC[8+U > 6 DQ+JL w#l$&>QH6% Uq!K-(*! D6 ? & ), DK 2>a K %% ,G , 1 zZ)6 &5% "3 / !0y\ k` ,o7 `G ,( Z ,,?VpXC ,. %N*M +D ,x , u % ,!)c c F8+d59¯e.6 /S QzZ),6K F.w@O3 %76% > +2KRA (! / >> +2KRA , > % ?A / >> +2KRA , G @0 % G"3 @ ,b DKWX %&(!1 [ k*> DKWX k G % k , A GWN *!+[ , V ,DWNf. J0 %Z , , .4 U . % ?V> +2KRA *? > +2KRA , > % %% . 0/ 7K", %A / >> +2KRABl 0# %N 6> %+C$ , S ,6K+ . %@%6 *!\?Fz 7a ,M'L A e.6 /c SzZ )U 6 AMZ > +2KRA , G @%@6%*!=PzZ)6 m b ,%N 6@ > 2X/K §Kª².G¢3K¦G.ª.´ M$&r%1 Q%%),*!Q -( !C" D ±. ? .¢j¢3¨¢ ·V¶XYK«H±¶ .¢jf Y « 3« s¦G¯ q....¢ ¤3m ¤ , «©¦G·«K3³.3. ¸&¹[º »¼Gn ½ kG ¿ oC9½ i.p7  qr'½ i.ps »'½K¼
3. IVM IN ODMG DATABASES
2% , 6 C # %A (G1 D6 C!F T hbv7M(!l 5 bD(%Ha . %A *e.60 *!PL )S0 u 0 ,6)= A%+ C !T 6 %1 mD(%A ,DWN %@(! a . % L C O(!% +6 \! Gw>?8 +BKRA D6 OH , > %# , , !T ),D C K , %*!cQ M u aK 6(!K)% 0WX ,%w>?@pq % ", `!S[ m./P6 \!G b , > ,r P H8 % M.> ,? w>?fpX# %Z * 0X/.M, ,6 V% 6 ,@/ !K% . . ( B % u pNhF;%wZGV k ) D J ", !4MG k VD %N ,6 O *$& *!),M[ ,DWN UYD%*!#% , 6 % M %+ 1- %N# 1 H!K F% ?b%#O, %+07 % @ F ) ,6K A% 6 ,l. F O !~ 2e.6> /~ K . %%)H[ $ O% (G1 %N * !D%C(), @%N/K%N % u g+khHIK%w
0/C ,'? { A hbvr %!K-(*! u (!#%6D%*e.6 . 0/# , !4M ", 0U
6 *!@!@G *!w>M30 %V!-0 ,@%Z G", %*!+ VO(!K% K6 \! "3 %\ (GZ ),.4 *e.60 V (),U A (>) %f 2 khbv7?3IK6>@ "3 % 6(!Kk! "3 !@ % M JG %+ #8 "3*!\MZG+" >$ , G = ,M4D./H), G )b[ hbvs!-0 , µ V"$Q!-0 ,4M$&>@$ >L V 2% µ M$& m %k0 % 0f , *!\M ", 6( !C(! 0U *!T . K?+6% M 78 %aK % . 6 ) H 3« 6%A µ ?+pY µ ! .%5 5 c @O,/$ ! ¦3¢K¦GK¢ * "!#%$& +( µ 6(!K % 0*MB D./P1U %)=T%>1% %@ ,P m G *?SCD , (G 1 zZ)6 AA% *$&% "!#%$'& +( K M )3 H$&0 H),U > *!c%N ),%+c % ?1< 7 *M4~ %N5$&0 µ (! µ M * "!#%$& +( µ %& "3 &G *!4? :&[ a J KL ,1%! "3 !A%!K % D *!4M "3 . % *!\?Vg50y\ .ZL %V pNhF;% k) > *!7! !) b %J f 5"$+M(%kL *$&% l ? ,+Å[0 p*z¹ º¯Â ½KzÅ p /  .rz @% , AOK!%# k6 \!G % M %N 6> *!cpNhF; , 6 %J A() %< *e.60 *!F µ D./m ", 6( ) * "!#%$& +( µ ", & +!K 07 7 y\ *!FD(%#a .*M G J (F G"3 & #D(%#a . 0 % 0XMK$& 5 %%)A \ D%aK % L> ! F 7hbv7?(z 2a ,M( % !> X ? { F %JphF; %' " 6(G *!4M* Z %6 0Z%4%N %' "!C#`$& +( U K $& c @ T 6) %b l ~hbv u (! U K 0f *e.60 *!(w>? ?bae(¹ Z¹ º  ½KzÅ p 1z¹ p*Ë Ã=0 p½K¼¹[ÂÅL?¹ c3'½ e Æ dr Ç if.jz > O !%7 56 \!G % M bpNhF; ,%N 6 *!lD./S %N/%N WX ,% µ $&0 =! 0P !K b `!K . 0[/~hbv} ,DWN %+ (7G y\ !=D./T 16 \! ? !*C %+ bG", , !S %%# bD(% a . %5$& "3 ,%%D ,?z a ,M % ! By\ \ !K0[/K) 5 < VC */. ?VpX %k*% u % *$&FF )U D kL xG &D , zZ)6 J3w>M. k KL , ~!K 0Q%b H ,6), l ! . 0[/$&> ,DWN > P Hhbvo ),.1D Cy\ > *!QD *6%C C! T , 0/
L %2 1 #6 \! *!F G/3 l @ %2 (!K 7 #! @ A +%N %2b @hbv©$&F(*"3+! ($k%B . D6 *!1D./7 Jy\ > *!1 */. ?fpXA % *%,MJ HpNhF;t$& 5 !r FWN K $& Z %%U ,]G l *$ ,!~aK 0*? :J # S ), %= 0 > C ) D caK %% %
K % . *!% % C , 8+d59~aK K %% ,%J (G2 , %+ #e.6 /b J "$©!`U 0 ,% u ? )K?M %FszZ),6K c,w>?H ) 0 %%%6 (G*M),"3 rlaK %% 'MBc%N ),.L $k !l ,O3 A* ! . 0[/.M'L 7 S) * *G ), /S . %N*MZ 1%> m 7 ,O, %H ms),"3 ©* ) /j (c . 6 c© (GTaU %% ' ? g2% )HzZ),6K F%@C% 6 ka % MZ% 1 @*G ), %+ . %N5H @ ),D 1>a K %% ,T% *$& A , G + % u ? )K?M : w>M4a .5( % u ? )K?M NO+F6*PA'h DQ+ > A]K w>M ,DWNm( % u ,? )?M + w>M D6K F( % u ,? )K? M +D-h FH ;JI +2+U > 6 DQ+8 -+F6*PA2DQ+ > A2U > 6DQ+ w>M@!©. ( A( % u ,? )?M VXW w>?5:2 ~ % u ,? )?M ....3¢K SzZ )6 b*w>?< A (G+$& ~b( A%# ), D( 0/F6 e.6 6 DQ+JL5L28 6 > -03ML5L
¸&¹[º »¼G½214¿ d431,%i hMe¼C¸&¹[ºja4¿#¹ i ½¼p65Ãe Z¹,hM ,%N 6*!%Cc ,O3 4?¯z6 , J ,%6% !Q S!KU c ,!S (Gb )CD T ",.*M2? )K?M+),"3 ¯U D6 c( s$B~!K c cq/K c 7$&>Gs%HU D6 1% $7C +!98;: ! ! !? & !=< u w>M\!T$B1 ),.+), b ,=(! !K B a .f( %% . *!A$&0 7 fq/ D./+$k ) !=>*$! $? A@ !C u $7C +!98;: ! ! !? & !=< u ww>?Z %B %B . %N $&0 $7C +!C u ! w>MK! )A +!K , [ }$&F", 6 %[ baK K %% , ! +! *$&4?Vpq %&# G % b( M3 $BA!K 5 #"3 %5 % c% & CB !C !C u w>?pXH!KU !K0 'M4),"3~ , P D6K # $A! 7 @q/K 7 + . %kC + , ,T% $7C +!C EDGF ! @ ! $ u # w>? zZ)6 71% *$&%J # . %%%2 (G&O3# # F +$kO, + H!K-(0 s #¯hbv@?kI(!*!QD GaK %!K H , U . %B (G& 5%%6 ! @aK%NJ(! *G &D GaK %! 5$ , , . %f a % %f 5aK%N )+ %f *e.60 *!#L Bpqv+h=? %7% > l! %> D %7*>~ k A * 7D *a%@PzZ)6 C? 7 G" ' , %5 K . %% %2 (JO,@ 7
event monitoring; change computation; view update.
D A T A B A S E
¸&¹[º(»¼G½IH ¿ ,5¼e'ʽ9iJi ½'i1Â9p b ¹`½' KJ\e\Ã=ÄZ¹LÅ[Â0p ¹zeEML7¹LÃ=½ { % > @ aK (!@ k " 6(G $& 5%6D , U . @O3J %%N . 2%N % 6K *!% & %6 0 JaK 6 )HHe.6 /.? {S%%6 1 (G7 *G K . %% % c , %% %A C%> )T6 l JX/K %@L 1%N U )S ThbvJUq% 0-(T!GS!s !c *e.60 *!rD./QpXv5h K . %% % ? HD *ar D ! -+* = ` + +POA2*,6 =P> ; * zZ)6 c=%
l% =%N/K. c )S l), G ,M5[ ~!K-(U ,S &Phbv µ M 1X$B F,!!0 , B"$t!>-(0 ,% MZ" ,?M µ (! "!#%$'& )( µ M*$& ,% * )&!5 6 U ,%c$k%T! % D *!¯D ",,?n< = µ ! µ = ! u [ H6%c$& ¯phF;V%H = ", 6( !(w>M2D6 * "!#%$& +( µ %V V ! ((!@ %V 0/A6%*! 1 ) D &[ ©[ V B ,%N 6 ,7 \1 BphF; L c ( > *?ocL6 ,G $'$' &y$z$ !>-(0 ,m (Gk(!6 $ *!T mD A 0 ! %5%5 A 6K ,%7 B 7- %N+0U G u G"3 k% %& 5"$24w !C% (!\M6 \!G % 1GU D6K % u %%D 0/1 ,m ,% MK(!1 %%D 0/A G % % !C J"3 % %w . ,*! C +"$ *!m 1D + ,U ! %2%J # 6K ,%# V #% ,(!H0 G u $&>4M L Z*># +aK %% # + "$S!-0 ,'MG"3 O3 % i ĽKbÊ z¹ hSÀ _ ' ½ pJidB ,29 p*ËZÀJÁ'ÄZ¼# 7 *"3> %5 5 b>a K %% ,b >U 6K % ", 0/(w>?1%* /.MZ%*%@!67 A *!H b 0 #KU % %+(!H!K %< Ta . %< "$ D *6%10 %# ) D [ FM'% *$&~ 2 zZ),6K
a>> +BKRA Ô
+2KRA Õ
¸&¹[º »¼G½P¾Ö'¿xJ7Å`Â iJi*¹{ÓVÊÂ0p*¹ze d m c Å[º(½ Z d ¼GÂ(¹LÊcÆAÄV½¼GÂ0p.e(¼i zZ),6K ~,T!K-( %1 K % 0/.ML *s"3 .1X/K b(!lL *>hbvrX/K ,M$&(O(!@ pNhF;=%) > *!\?fpXAzZ )6 +,M 2 o r?!v : sDD "K G % 2 %G r (!0 ,b D6K 6sM D./ $&b%& *.&F D6 5 . 6 )1bA ,!0 ,CaU %% u ,? )?M lzZ)6 bM +U -+FJA %1n !:x$& *% +U > 6D)+ % >w>?s< ,Mk *$B "3 *M (m !: D6 b /Q *G %$& 1cme.6 / u ,? )K? M4c GWN w>?#:J % KM4D/ ×qØ %+ *.+6%)C !GCT !K 0m )m A%NG @!D%@` r*%H F%m~ !Q ~6%F , !T", 6A B AG D6 7 T ApNhF; u !K . Z @ , (G2$B ,6 `!F*"3#D H), G *!F0 @ D6K #$B # 5 !:5w2 m %N 6>+$&>= ,DWN > %@!7#. hbvt , JD(%%k B", 6,MD [ 56% )@ 2$" 6J 7) > U 5 +% (!bpNhF;f?pqk$& D +% F J (Gk + 6 6K& 2X$ 7phF;V%k> @hbv© DKWX %k 1!K +(!C% *M
% > ", 0/.? :2Ca + u + ), DK @[ wkHphF;r) > *! D./~ . )cH! 0b$%1) ", l@ , P 2zZ )6 mKM(! Z ,2), !CD./+WN ) 7! 0@$&0 µ MK m D R 5zZ),6K F?QIKC ma m"3 .Aq/ %7$> ,M
% > ", 0/.M ÜG,3 ¢ Ý (! àK¦ 3³ á3¢3¢3 u $& 7 AGU D6K @ce.6 %N H %2 5 !:5w>M (!b #a 7hbv]%5 +.-0/1.+=+YA ; =P> "$+M( @>a %& % ,!4M % > ", 0/.M r ×:Ø s ! r â µ Þ ×:Ø sKHzZ),6K #K? . 60 ,FD (!C %&FzZ)6 1,#%J%k[ , G$&% l ,q ? +.-0/1.+[+BABl < 1 %%&%k *e.60 *! 1D(%+!GKM%&0&% %6| .k @-( 0 & 1%f B ,
*! D/@ J!K 03w>?2! +D , %*", D l {> TS$^ ,DWN >b%m * !s ( */2 (G ( 5 f"$ u ? )K?M,G[ Z ÜG,, ¢ Ý w>M @"K$©A6%N +2KRAnÕ+2KRA
+.-0/1.+[+BA ; =P>
.
. .
T×:Ø
µ¡Þ µ¡Þ µ¡Þ µ¡Þ µ¡Þ
µ¡Þ T×:Ø µ Þ ¡ T×:Ø
Ô
×:Ø ´ÙLÚ Û
´ÙLÚ Û
×:Ø
×:Ø ÙLÚ Û ´ÙLÚ Û
. . . . . . . . . .
T×:Ø
T×:Ø ´ÙLÚ Û
´ÙLÚ Û T×:Ø
T×:Ø
ÙLÚ Û T×:Ø
´ÙLÚ Û T×:Ø
¸&¹[º »¼G½P¾(¾(¿vJ7Ëfe[eEi*¹ ºPÂ 3©Â(¹zp ½'Â0ZÊ,½ ,+Å[Â0 IK"3 6 \! 1 ,% u ~ *$&%AGUqFPzZ),6 HGw * 1(),$&l ,DWN %7 ,. D6K m H m"$+M D6KZ /+Gy\ Z B!& GWN > *!@# " >$+?V:2%'%6'M WN )+ J!K 0 V *e.60 1 %%5 CD(%1!?@pXT A %1 %N )M /b # ,DWN %2[ , $&= %N *!F > (%D 1 %N 6> *!4M,% 7)3 0% %% G /A + %% D(%H!G=s ! c 6 C>), %1 c b"$+? :2%&%6>4M( . 4>) %& 1D / >> +BKRA ! > +2KRA "$&%J # , 6 *!D./ . )7 5 ".J! ? z f *% ,%f (% ,M$ 0V@aK 0! %> K ,A ), 0 %V! *!#D./+ B %V7zZ )6 1%#Phbv L @$&>c 7 e6 %N#%5 ". u D *6%20G > %V & "3 .% 0-* ,%k!> ",*!AL B (G hbvE"$ , G s Gw>M F% *!QpXv5h !H% %6>P *MV$& QaK 6K *!4MV0 ", 6 %7 mphF; u %w7%% .U G *!A$&0 1 (G6 \!G 5 , 6 k>) % u %! % D *!
b < !)1%6D% > 'M!CF (G 6 JHzZ),6K 1,*w !b H K , )3G %) %2 Ahbv@?\7!> % *$©>) %+G 1 *!F Ahbv$&% MZ ) J %Nk ' L )77e.6> /1 G"3 @ ,UYG *! " >$ C A %N# B , ), )F . f6 \!G %5 m A U
% (!)lhbv7MB!s &. ( H)3 %NC >U > ` ,#$& 5 V"K$=*!%46 \! )K? (JUY 0U *G 6(!K %!K )+ JaK%N )# *! a .*M3 >U 6 )7 ` *!s"$&% (% D r%N 6(!K !r!K &L G ( /s {? G"`!Kk5!Ky\> . ` K ), ]L . ) = 6 %5 b >U . 0/C6 \!G @1%6D%>< Id59~"$&%A ?J:J ,6),F %N/K%N */K%7 "3C!D(%m , ,)/l!SO3/=L U c[ 7 fD %# >L *!c c"$ !-0 ,% M0@! .% G", , !A %%V 5D(%D %V$& *%1 6 V% , 6K " >$&% *CD 5 . 0/ . *! $& ,6K& %%)1D%/~ *e.60 C %%A c kD(%mD %A[ k6 U !G b ,% M$&r ,6 !lD b baK % ",m Q ,6 ,'MZ% A$*"3 !~ %%)FD%!m[ @% , A6 U !G % ? \6),b> {?Q ,%H u5x u
9u Bxw xv
w 0* (2! K %7 MZ*G Z !GU$kG 6%) "0 ,KU . % ?V8 ", %+ ) D >a K %% ,%5 C 6K 7(),%5 b"$&% ? :2 0 ,6)=0 ' ,% 0/ % 7D %+0*G a K %%"3 %%k m ),6(),H(!S C 6.1 P pXv5hR D FM%+$!K ?mzZ( 0/.Mfi *MK / 0 > > ` bPa (!K*!=L & Chbv u D % ! %@ Chbv 0 % 0w$ !>-(0 ,A `)6()2D%*!1 8+d59?3:2 0 6)8+d59C%N/K.a7% ,!K , K *!4M *!@D/5 . ! !K % u ,? )?F K WX ,% M\WN ,%w#S ), DK m % .GU ,Q J be6 /.?P:Jl . 6 \! m Q.% D 1 &"K$s!A J6KaK /1 KL ,4?fpX 6 %N/%N FM
$B&! 5 V%N %6 0 %V . *!K ! % ?IKe.60 U )3G % 6 \! %7 ~hbv2%1P % ,%b T % % (!F!K %J , /.M$& %&$#%6 2 Z6 \! + % !K-(*!AD./@ J8 ` *!H . 0/.?B6% M /s! S C G"`!KTP!0 0/r .D F% , 6 ¯ +pXv5h K ,D FMD6Kk & * ,%B \ J 6 %2(!7 & *!A !K [ F ,DWN > ! . 0 % MB$& C) *G /l% 0`/)c pqv+h_%O MVO3%701 m!0| 6 @ H * l > lD - % >a *!F !1$kG 6% % ?+hb6 0 v *%$B#G", , !C %%)1D(%5a . % [ m"$&% ,. )SG D0 /Q67D 7 BWX ,% [ 6 \!G H , G % ?zZ 0/.MJ:2 (*W[W>b A0 < %C ) U
0 %2L 5 @ . Z . 7 kIK;"K$&%a K %%"3 %%{ %&% k ' 2 *!K% ' 2"3 / U ,% (GV(*"3k K " ! !JWN6%N 0-(*G 1L G"3B[
`G ,( ' 7 ,DWN UYD%*!F!D(%% ?B+ %%~0> % C < !)1 Z[ G b (Gk%& %% /$& C U [ )2!>L *!#6 \! % M,!5 , % %f %$&
% 5D A k" >$s ),6),J(!7 k . %% \6 \!G K , )3G ,'? 6.
CONCLUSIONS
V% , 6 ,# K % . *!5> %\ fL *$&)2% .Z . % b `G ,F "K 6%k$ O\?pY2%& ,# Z[$j J G"3 & pqv+h K ,D [ E "3 .+% 0-(*G 'M' bphF;) G ,'M m6 \! # ()3 X '5 %J #- %N5 ), DK ,c pqv+h] D + ,. a DKWX V!D(%Y% ,0$B O% [ J+$& ! k `%%k fhbv-(0 ,7$& % WX ,%%V$ %),) )3G , [6 ,% M%J , G ,%2!be.6(. -* '? cmÊ fe' Å[' ½ º½Ãc9½ [pJi7h=?4:2O. O *$& 0U !),%2 @%6 2 V !B ,.$* 0 cIK , G % !B ,1U %% ,b C g20 *! +)3! u i2 .J; G3,,w>?
7. REFERENCES
0> G(@?:2 GW`WJ(!CzB? ;Z `G*?(pq v$&% ?pq !#"+MK (), %2K MZ*,? 7h=? E? ! /.MgA? ?g52 {0*Mh=? ?z O 4M@?&9? &5 {M h=?(9V? hb*:J6 0y\,M ? zB?56),. 'MKgA?
Alvaro A.A. Fernandes
Norman W. Paton
Dept. of Computer Science University of Manchester Manchester M13 9PL, UK
Dept. of Computer Science University of Manchester Manchester M13 9PL, UK
Dept. of Computer Science University of Manchester Manchester M13 9PL, UK
[email protected]
[email protected]
[email protected]
ABSTRACT
!#"$&%'(%') *$&+%),-*. 0/ $&0 1 2!"3 4!5$ ,6%)7(! 859': , )/.? %@ *%%# A " 1 B% , 6 %+ C 1 D E . 0/F)1G *!H"$&% ?JIK 1L *M %N $B OP Q %A ,D R%1D Q ,-*!S T , J%U ),% ?B;V ,% %& (GaK& VA% . 0-(#!7$ ,6% )1 GWN2[ . 6%) , ), , L
%6 % [ m F !l% 6 ,4?I ,~! %> D % D /b @ % = . a2[ 5 7 . D6 ,%< K % . *! T ( H(! ,. %N %C %c$&0 $ OD./ b >U %*G > % ?kI ,bA 6(!K %J!b ,. %k 7L6K 6 5$B O ? 2. TECHNICAL BACKGROUND
1.
INTRODUCTION
: "$o!K-( lL 0X/Q%1" 6(D C[ /S!GD(% n *G ,% ?BpqJ(%&D FO *$&b[ 2% , ` # + . 0 hbvx "3 /T b(), %#D S!A @ ),.#Gy\ 0*?z B % *% 'MK0%), 0/m!K %0 D J @ K , )3G 2 () %5 . 0/.M {? ? M\ 6 + 7(),% ` ) . "$x)3'?TpX. %N7Qhbv2%7%@ *%*!l%7
%6 0V (2) *$&)5*$ %%V B .Z , B f / )2 /Fc!G1$k ,6%)m ,. a % ?2%$sG * ,D , % %N6(*"3 `!U D 0 /AD KL*% D ~ H P , 6 H)3 (!)3~"$
Permission to make digital or hard copies of all or part of this work for personal or classroom use is granted without fee provided that copies are not made or distributed for profit or commercial advantage and that copies bear this notice and the full citation on the first page. To copy otherwise, to republish, to post on servers or to redistribute to lists, requires prior specific permission and/or a fee. DOLAP ’2000 Washington, D.C, USA Copyright 2000 ACM 0-89791-88-6/97/05 .. 5.00
%+% > S. !6 %+a %5 J8 / U %%)= ,%A6% !S P m% 6 ,4M% 0-(* 0/P ,%m 1U !mT85;&i5x .M G Z(!FUYg+j G ? -(0 ,H ),6) u 8 /F KU ),6) u 8+d59w>? I , 5{ G q/F$&0 F %J ! ' %2%%6 *! ~ *?H8 C$&P!>U -( %1 b", !r ,sq/K % ?zZ),6K SH%ra 8 K? ,333l,, ,¡3¢..¢£,K¤¥ ¢3¢,K¦G§3¨.¢3©G¢3K¦G.ªrK «Z¬ ¢3¢,K¦G§3¨.¢3¨,3¦ª,.,jG®K,¢¯ª.Z¬ ¢3¢,K¦G§3¨.¢3©G¢3K¦G.ª33..3'¬ °\¬ ,333Q.3¢G«.¢ ,¡3¢..¢±K3¢G«3¢Kj¤¥ ¢3¢,K¦G§3¨.¢3©G¢3K¦G.ªrK «Z¬ ¢3¢,K¦G§3¨.¢3©G¢3K¦G.ª33..3'¬ ..,¢K¦,KG®¦G,¢.²,*«KK,³.3.´¯*«K3³.3. ¦*.µ.,K*«KK3³.3f¶3¶Y..¢f¬°4¬ ,333r*«K3³.3¯,¡,¢..KP,K,G ,¡3¢..¢·«KK,³.3¤Q¥ ¢3¢,K¦G§3¨.¢3¨,3¦ª,.,3.ª¯,33,³f¬ ¢3¢,K¦G§3¨.¢3©,¢²K,K´s3.3.¢K'¬ ..,¢K¦,KG®¦G.3¢G«.¢¯..¢ ¦*.µ.,K.K,¢G«.¢f¶3¶X*«K3³.3.'¬ ¢3¢,K¦G§3¨.¢3 «KK3³33l«(Kª.,f¬ °\¬ ¸&¹[º »¼G½P¾(¿#ÀJÁ'Â(Ã=ÄfÅ[½=Æ1ÇCÈ]É'Ê˽Ã=Â
zZ)6 J2!K %VAa k8+d59me.6 /# G"3 fzZ )6 5(! "K$r!K-(*!76% )a 6 ,= % ?m:2caK 6K ~ `~% % `G *!C. " !$#%#j!m , *!\?VJ %6 0 )@aKU 6D ,M$&
64M " 6(G %B J ) '8+d59Te.6 /.?fUqg5 ! %JAe.6> / . %%) K 3>F % 0/C % AD )7 (G 6%*!FH%N ng+khHI% % `! '?:2%&$ % k , , !4M3 7@+BA % - %V ka .V0%*% u ,? )K? M
CEDGFH ;JI +.+2K w>MZm",G `D 1 ),)C G"3 + 7 ,DWN > %@c (5aU . u ,? )?M + w>Mf(!~ " ,!0 , u ? )K?M 6 > -03ML M4= % *%A1" 6 ,6% /m 6+ Gw>?k:2%k$ f%2 + , !4MK : , > #% 0-( %+0 % + w>? U % ! %V k `!A(!@ " ,!0 , u " 6 ,6% 0/@ 6 b +>a Gw>MK *,+.-0/1.+ 5!K-( %J1%N 6 6K 5L m %6 0 %A > 6 ! u ? )K?M KRA2* -03ZC[8+U > 6DQ+JL28Q4 =P> -03ZNX8 - U > 6 DQ+JL5L w\!++. ( ," D u ,? )K? M VXW w (G*#D 6%*! F [ 7 b %@%N % ?TIK6SF%N 6 6 ,%%N %@ 4 =P> aK %% % u ? )K?M 4 =P> -03ZC[8+U > 6 DQ+JL w#l$&>QH6% Uq!K-(*! D6 ? & ), DK 2>a K %% ,G , 1 zZ)6 &5% "3 / !0y\ k` ,o7 `G ,( Z ,,?VpXC ,. %N*M +D ,x , u % ,!)c c F8+d59¯e.6 /S QzZ),6K F.w@O3 %76% > +2KRA (! / >> +2KRA , > % ?A / >> +2KRA , G @0 % G"3 @ ,b DKWX %&(!1 [ k*> DKWX k G % k , A GWN *!+[ , V ,DWNf. J0 %Z , , .4 U . % ?V> +2KRA *? > +2KRA , > % %% . 0/ 7K", %A / >> +2KRABl 0# %N 6> %+C$ , S ,6K+ . %@%6 *!\?Fz 7a ,M'L A e.6 /c SzZ )U 6 AMZ > +2KRA , G @%@6%*!=PzZ)6 m b ,%N 6@ > 2X/K §Kª².G¢3K¦G.ª.´ M$&r%1 Q%%),*!Q -( !C" D ±. ? .¢j¢3¨¢ ·V¶XYK«H±¶ .¢jf Y « 3« s¦G¯ q....¢ ¤3m ¤ , «©¦G·«K3³.3. ¸&¹[º »¼Gn ½ kG ¿ oC9½ i.p7  qr'½ i.ps »'½K¼
3. IVM IN ODMG DATABASES
2% , 6 C # %A (G1 D6 C!F T hbv7M(!l 5 bD(%Ha . %A *e.60 *!PL )S0 u 0 ,6)= A%+ C !T 6 %1 mD(%A ,DWN %@(! a . % L C O(!% +6 \! Gw>?8 +BKRA D6 OH , > %# , , !T ),D C K , %*!cQ M u aK 6(!K)% 0WX ,%w>?@pq % ", `!S[ m./P6 \!G b , > ,r P H8 % M.> ,? w>?fpX# %Z * 0X/.M, ,6 V% 6 ,@/ !K% . . ( B % u pNhF;%wZGV k ) D J ", !4MG k VD %N ,6 O *$& *!),M[ ,DWN UYD%*!#% , 6 % M %+ 1- %N# 1 H!K F% ?b%#O, %+07 % @ F ) ,6K A% 6 ,l. F O !~ 2e.6> /~ K . %%)H[ $ O% (G1 %N * !D%C(), @%N/K%N % u g+khHIK%w
0/C ,'? { A hbvr %!K-(*! u (!#%6D%*e.6 . 0/# , !4M ", 0U
6 *!@!@G *!w>M30 %V!-0 ,@%Z G", %*!+ VO(!K% K6 \! "3 %\ (GZ ),.4 *e.60 V (),U A (>) %f 2 khbv7?3IK6>@ "3 % 6(!Kk! "3 !@ % M JG %+ #8 "3*!\MZG+" >$ , G = ,M4D./H), G )b[ hbvs!-0 , µ V"$Q!-0 ,4M$&>@$ >L V 2% µ M$& m %k0 % 0f , *!\M ", 6( !C(! 0U *!T . K?+6% M 78 %aK % . 6 ) H 3« 6%A µ ?+pY µ ! .%5 5 c @O,/$ ! ¦3¢K¦GK¢ * "!#%$& +( µ 6(!K % 0*MB D./P1U %)=T%>1% %@ ,P m G *?SCD , (G 1 zZ)6 AA% *$&% "!#%$'& +( K M )3 H$&0 H),U > *!c%N ),%+c % ?1< 7 *M4~ %N5$&0 µ (! µ M * "!#%$& +( µ %& "3 &G *!4? :&[ a J KL ,1%! "3 !A%!K % D *!4M "3 . % *!\?Vg50y\ .ZL %V pNhF;% k) > *!7! !) b %J f 5"$+M(%kL *$&% l ? ,+Å[0 p*z¹ º¯Â ½KzÅ p /  .rz @% , AOK!%# k6 \!G % M %N 6> *!cpNhF; , 6 %J A() %< *e.60 *!F µ D./m ", 6( ) * "!#%$& +( µ ", & +!K 07 7 y\ *!FD(%#a .*M G J (F G"3 & #D(%#a . 0 % 0XMK$& 5 %%)A \ D%aK % L> ! F 7hbv7?(z 2a ,M( % !> X ? { F %JphF; %' " 6(G *!4M* Z %6 0Z%4%N %' "!C#`$& +( U K $& c @ T 6) %b l ~hbv u (! U K 0f *e.60 *!(w>? ?bae(¹ Z¹ º  ½KzÅ p 1z¹ p*Ë Ã=0 p½K¼¹[ÂÅL?¹ c3'½ e Æ dr Ç if.jz > O !%7 56 \!G % M bpNhF; ,%N 6 *!lD./S %N/%N WX ,% µ $&0 =! 0P !K b `!K . 0[/~hbv} ,DWN %+ (7G y\ !=D./T 16 \! ? !*C %+ bG", , !S %%# bD(% a . %5$& "3 ,%%D ,?z a ,M % ! By\ \ !K0[/K) 5 < VC */. ?VpX %k*% u % *$&FF )U D kL xG &D , zZ)6 J3w>M. k KL , ~!K 0Q%b H ,6), l ! . 0[/$&> ,DWN > P Hhbvo ),.1D Cy\ > *!QD *6%C C! T , 0/
L %2 1 #6 \! *!F G/3 l @ %2 (!K 7 #! @ A +%N %2b @hbv©$&F(*"3+! ($k%B . D6 *!1D./7 Jy\ > *!1 */. ?fpXA % *%,MJ HpNhF;t$& 5 !r FWN K $& Z %%U ,]G l *$ ,!~aK 0*? :J # S ), %= 0 > C ) D caK %% %
K % . *!% % C , 8+d59~aK K %% ,%J (G2 , %+ #e.6 /b J "$©!`U 0 ,% u ? )K?M %FszZ),6K c,w>?H ) 0 %%%6 (G*M),"3 rlaK %% 'MBc%N ),.L $k !l ,O3 A* ! . 0[/.M'L 7 S) * *G ), /S . %N*MZ 1%> m 7 ,O, %H ms),"3 ©* ) /j (c . 6 c© (GTaU %% ' ? g2% )HzZ),6K F%@C% 6 ka % MZ% 1 @*G ), %+ . %N5H @ ),D 1>a K %% ,T% *$& A , G + % u ? )K?M : w>M4a .5( % u ? )K?M NO+F6*PA'h DQ+ > A]K w>M ,DWNm( % u ,? )?M + w>M D6K F( % u ,? )K? M +D-h FH ;JI +2+U > 6 DQ+8 -+F6*PA2DQ+ > A2U > 6DQ+ w>M@!©. ( A( % u ,? )?M VXW w>?5:2 ~ % u ,? )?M ....3¢K SzZ )6 b*w>?< A (G+$& ~b( A%# ), D( 0/F6 e.6 6 DQ+JL5L28 6 > -03ML5L
¸&¹[º »¼G½214¿ d431,%i hMe¼C¸&¹[ºja4¿#¹ i ½¼p65Ãe Z¹,hM ,%N 6*!%Cc ,O3 4?¯z6 , J ,%6% !Q S!KU c ,!S (Gb )CD T ",.*M2? )K?M+),"3 ¯U D6 c( s$B~!K c cq/K c 7$&>Gs%HU D6 1% $7C +!98;: ! ! !? & !=< u w>M\!T$B1 ),.+), b ,=(! !K B a .f( %% . *!A$&0 7 fq/ D./+$k ) !=>*$! $? A@ !C u $7C +!98;: ! ! !? & !=< u ww>?Z %B %B . %N $&0 $7C +!C u ! w>MK! )A +!K , [ }$&F", 6 %[ baK K %% , ! +! *$&4?Vpq %&# G % b( M3 $BA!K 5 #"3 %5 % c% & CB !C !C u w>?pXH!KU !K0 'M4),"3~ , P D6K # $A! 7 @q/K 7 + . %kC + , ,T% $7C +!C EDGF ! @ ! $ u # w>? zZ)6 71% *$&%J # . %%%2 (G&O3# # F +$kO, + H!K-(0 s #¯hbv@?kI(!*!QD GaK %!K H , U . %B (G& 5%%6 ! @aK%NJ(! *G &D GaK %! 5$ , , . %f a % %f 5aK%N )+ %f *e.60 *!#L Bpqv+h=? %7% > l! %> D %7*>~ k A * 7D *a%@PzZ)6 C? 7 G" ' , %5 K . %% %2 (JO,@ 7
event monitoring; change computation; view update.
D A T A B A S E
¸&¹[º(»¼G½IH ¿ ,5¼e'ʽ9iJi ½'i1Â9p b ¹`½' KJ\e\Ã=ÄZ¹LÅ[Â0p ¹zeEML7¹LÃ=½ { % > @ aK (!@ k " 6(G $& 5%6D , U . @O3J %%N . 2%N % 6K *!% & %6 0 JaK 6 )HHe.6 /.? {S%%6 1 (G7 *G K . %% % c , %% %A C%> )T6 l JX/K %@L 1%N U )S ThbvJUq% 0-(T!GS!s !c *e.60 *!rD./QpXv5h K . %% % ? HD *ar D ! -+* = ` + +POA2*,6 =P> ; * zZ)6 c=%
l% =%N/K. c )S l), G ,M5[ ~!K-(U ,S &Phbv µ M 1X$B F,!!0 , B"$t!>-(0 ,% MZ" ,?M µ (! "!#%$'& )( µ M*$& ,% * )&!5 6 U ,%c$k%T! % D *!¯D ",,?n< = µ ! µ = ! u [ H6%c$& ¯phF;V%H = ", 6( !(w>M2D6 * "!#%$& +( µ %V V ! ((!@ %V 0/A6%*! 1 ) D &[ ©[ V B ,%N 6 ,7 \1 BphF; L c ( > *?ocL6 ,G $'$' &y$z$ !>-(0 ,m (Gk(!6 $ *!T mD A 0 ! %5%5 A 6K ,%7 B 7- %N+0U G u G"3 k% %& 5"$24w !C% (!\M6 \!G % 1GU D6K % u %%D 0/1 ,m ,% MK(!1 %%D 0/A G % % !C J"3 % %w . ,*! C +"$ *!m 1D + ,U ! %2%J # 6K ,%# V #% ,(!H0 G u $&>4M L Z*># +aK %% # + "$S!-0 ,'MG"3 O3 % i ĽKbÊ z¹ hSÀ _ ' ½ pJidB ,29 p*ËZÀJÁ'ÄZ¼# 7 *"3> %5 5 b>a K %% ,b >U 6K % ", 0/(w>?1%* /.MZ%*%@!67 A *!H b 0 #KU % %+(!H!K %< Ta . %< "$ D *6%10 %# ) D [ FM'% *$&~ 2 zZ),6K
a>> +BKRA Ô
+2KRA Õ
¸&¹[º »¼G½P¾Ö'¿xJ7Å`Â iJi*¹{ÓVÊÂ0p*¹ze d m c Å[º(½ Z d ¼GÂ(¹LÊcÆAÄV½¼GÂ0p.e(¼i zZ),6K ~,T!K-( %1 K % 0/.ML *s"3 .1X/K b(!lL *>hbvrX/K ,M$&(O(!@ pNhF;=%) > *!\?fpXAzZ )6 +,M 2 o r?!v : sDD "K G % 2 %G r (!0 ,b D6K 6sM D./ $&b%& *.&F D6 5 . 6 )1bA ,!0 ,CaU %% u ,? )?M lzZ)6 bM +U -+FJA %1n !:x$& *% +U > 6D)+ % >w>?s< ,Mk *$B "3 *M (m !: D6 b /Q *G %$& 1cme.6 / u ,? )K? M4c GWN w>?#:J % KM4D/ ×qØ %+ *.+6%)C !GCT !K 0m )m A%NG @!D%@` r*%H F%m~ !Q ~6%F , !T", 6A B AG D6 7 T ApNhF; u !K . Z @ , (G2$B ,6 `!F*"3#D H), G *!F0 @ D6K #$B # 5 !:5w2 m %N 6>+$&>= ,DWN > %@!7#. hbvt , JD(%%k B", 6,MD [ 56% )@ 2$" 6J 7) > U 5 +% (!bpNhF;f?pqk$& D +% F J (Gk + 6 6K& 2X$ 7phF;V%k> @hbv© DKWX %k 1!K +(!C% *M
% > ", 0/.? :2Ca + u + ), DK @[ wkHphF;r) > *! D./~ . )cH! 0b$%1) ", l@ , P 2zZ )6 mKM(! Z ,2), !CD./+WN ) 7! 0@$&0 µ MK m D R 5zZ),6K F?QIKC ma m"3 .Aq/ %7$> ,M
% > ", 0/.M ÜG,3 ¢ Ý (! àK¦ 3³ á3¢3¢3 u $& 7 AGU D6K @ce.6 %N H %2 5 !:5w>M (!b #a 7hbv]%5 +.-0/1.+=+YA ; =P> "$+M( @>a %& % ,!4M % > ", 0/.M r ×:Ø s ! r â µ Þ ×:Ø sKHzZ),6K #K? . 60 ,FD (!C %&FzZ)6 1,#%J%k[ , G$&% l ,q ? +.-0/1.+[+BABl < 1 %%&%k *e.60 *! 1D(%+!GKM%&0&% %6| .k @-( 0 & 1%f B ,
*! D/@ J!K 03w>?2! +D , %*", D l {> TS$^ ,DWN >b%m * !s ( */2 (G ( 5 f"$ u ? )K?M,G[ Z ÜG,, ¢ Ý w>M @"K$©A6%N +2KRAnÕ+2KRA
+.-0/1.+[+BA ; =P>
.
. .
T×:Ø
µ¡Þ µ¡Þ µ¡Þ µ¡Þ µ¡Þ
µ¡Þ T×:Ø µ Þ ¡ T×:Ø
Ô
×:Ø ´ÙLÚ Û
´ÙLÚ Û
×:Ø
×:Ø ÙLÚ Û ´ÙLÚ Û
. . . . . . . . . .
T×:Ø
T×:Ø ´ÙLÚ Û
´ÙLÚ Û T×:Ø
T×:Ø
ÙLÚ Û T×:Ø
´ÙLÚ Û T×:Ø
¸&¹[º »¼G½P¾(¾(¿vJ7Ëfe[eEi*¹ ºPÂ 3©Â(¹zp ½'Â0ZÊ,½ ,+Å[Â0 IK"3 6 \! 1 ,% u ~ *$&%AGUqFPzZ),6 HGw * 1(),$&l ,DWN %7 ,. D6K m H m"$+M D6KZ /+Gy\ Z B!& GWN > *!@# " >$+?V:2%'%6'M WN )+ J!K 0 V *e.60 1 %%5 CD(%1!?@pXT A %1 %N )M /b # ,DWN %2[ , $&= %N *!F > (%D 1 %N 6> *!4M,% 7)3 0% %% G /A + %% D(%H!G=s ! c 6 C>), %1 c b"$+? :2%&%6>4M( . 4>) %& 1D / >> +BKRA ! > +2KRA "$&%J # , 6 *!D./ . )7 5 ".J! ? z f *% ,%f (% ,M$ 0V@aK 0! %> K ,A ), 0 %V! *!#D./+ B %V7zZ )6 1%#Phbv L @$&>c 7 e6 %N#%5 ". u D *6%20G > %V & "3 .% 0-* ,%k!> ",*!AL B (G hbvE"$ , G s Gw>M F% *!QpXv5h !H% %6>P *MV$& QaK 6K *!4MV0 ", 6 %7 mphF; u %w7%% .U G *!A$&0 1 (G6 \!G 5 , 6 k>) % u %! % D *!
b < !)1%6D% > 'M!CF (G 6 JHzZ),6K 1,*w !b H K , )3G %) %2 Ahbv@?\7!> % *$©>) %+G 1 *!F Ahbv$&% MZ ) J %Nk ' L )77e.6> /1 G"3 @ ,UYG *! " >$ C A %N# B , ), )F . f6 \!G %5 m A U
% (!)lhbv7MB!s &. ( H)3 %NC >U > ` ,#$& 5 V"K$=*!%46 \! )K? (JUY 0U *G 6(!K %!K )+ JaK%N )# *! a .*M3 >U 6 )7 ` *!s"$&% (% D r%N 6(!K !r!K &L G ( /s {? G"`!Kk5!Ky\> . ` K ), ]L . ) = 6 %5 b >U . 0/C6 \!G @1%6D%>< Id59~"$&%A ?J:J ,6),F %N/K%N */K%7 "3C!D(%m , ,)/l!SO3/=L U c[ 7 fD %# >L *!c c"$ !-0 ,% M0@! .% G", , !A %%V 5D(%D %V$& *%1 6 V% , 6K " >$&% *CD 5 . 0/ . *! $& ,6K& %%)1D%/~ *e.60 C %%A c kD(%mD %A[ k6 U !G b ,% M$&r ,6 !lD b baK % ",m Q ,6 ,'MZ% A$*"3 !~ %%)FD%!m[ @% , A6 U !G % ? \6),b> {?Q ,%H u5x u
9u Bxw xv
w 0* (2! K %7 MZ*G Z !GU$kG 6%) "0 ,KU . % ?V8 ", %+ ) D >a K %% ,%5 C 6K 7(),%5 b"$&% ? :2 0 ,6)=0 ' ,% 0/ % 7D %+0*G a K %%"3 %%k m ),6(),H(!S C 6.1 P pXv5hR D FM%+$!K ?mzZ( 0/.Mfi *MK / 0 > > ` bPa (!K*!=L & Chbv u D % ! %@ Chbv 0 % 0w$ !>-(0 ,A `)6()2D%*!1 8+d59?3:2 0 6)8+d59C%N/K.a7% ,!K , K *!4M *!@D/5 . ! !K % u ,? )?F K WX ,% M\WN ,%w#S ), DK m % .GU ,Q J be6 /.?P:Jl . 6 \! m Q.% D 1 &"K$s!A J6KaK /1 KL ,4?fpX 6 %N/%N FM
$B&! 5 V%N %6 0 %V . *!K ! % ?IKe.60 U )3G % 6 \! %7 ~hbv2%1P % ,%b T % % (!F!K %J , /.M$& %&$#%6 2 Z6 \! + % !K-(*!AD./@ J8 ` *!H . 0/.?B6% M /s! S C G"`!KTP!0 0/r .D F% , 6 ¯ +pXv5h K ,D FMD6Kk & * ,%B \ J 6 %2(!7 & *!A !K [ F ,DWN > ! . 0 % MB$& C) *G /l% 0`/)c pqv+h_%O MVO3%701 m!0| 6 @ H * l > lD - % >a *!F !1$kG 6% % ?+hb6 0 v *%$B#G", , !C %%)1D(%5a . % [ m"$&% ,. )SG D0 /Q67D 7 BWX ,% [ 6 \!G H , G % ?zZ 0/.MJ:2 (*W[W>b A0 < %C ) U
0 %2L 5 @ . Z . 7 kIK;"K$&%a K %%"3 %%{ %&% k ' 2 *!K% ' 2"3 / U ,% (GV(*"3k K " ! !JWN6%N 0-(*G 1L G"3B[
`G ,( ' 7 ,DWN UYD%*!F!D(%% ?B+ %%~0> % C < !)1 Z[ G b (Gk%& %% /$& C U [ )2!>L *!#6 \! % M,!5 , % %f %$&
% 5D A k" >$s ),6),J(!7 k . %% \6 \!G K , )3G ,'? 6.
CONCLUSIONS
V% , 6 ,# K % . *!5> %\ fL *$&)2% .Z . % b `G ,F "K 6%k$ O\?pY2%& ,# Z[$j J G"3 & pqv+h K ,D [ E "3 .+% 0-(*G 'M' bphF;) G ,'M m6 \! # ()3 X '5 %J #- %N5 ), DK ,c pqv+h] D + ,. a DKWX V!D(%Y% ,0$B O% [ J+$& ! k `%%k fhbv-(0 ,7$& % WX ,%%V$ %),) )3G , [6 ,% M%J , G ,%2!be.6(. -* '? cmÊ fe' Å[' ½ º½Ãc9½ [pJi7h=?4:2O. O *$& 0U !),%2 @%6 2 V !B ,.$* 0 cIK , G % !B ,1U %% ,b C g20 *! +)3! u i2 .J; G3,,w>?
7. REFERENCES
0> G(@?:2 GW`WJ(!CzB? ;Z `G*?(pq v$&% ?pq !#"+MK (), %2K MZ*,? 7h=? E? ! /.MgA? ?g52 {0*Mh=? ?z O 4M@?&9? &5 {M h=?(9V? hb*:J6 0y\,M ? zB?56),. 'MKgA?
