Re: [HELP]Database

[Hoang Quoc-Hung <hoang@daimi.aau.dk>]

> 
> Nh~ gi` to^i ddu*o*.c bie^'t la` relationship database ddu*o*.c a'p
> du.ng ro^.ng ra~i trong thu*o*ng ma.i , hie^.n gio*` ng` ta ddang xem
> xet object-oriented database nhu*ng chu*a co' u*'ng du.ng na`o dda'p
> u*'ng ddu*o*.c ??? 


> Ngoa`i ra dde^? qua?n ly' database tre^n die^.n ro^.ng , nh` ng` truy
> ca^.p thi` mo^ hi`nh client/server va^~n la` chu? ye^'u hie^.n nay ???
> 

Chi. Hue tha^n me^'n,
Tha^'y anh PhuBinh dda~ gioi thieu sa'ch RDB ro^`i, toi tro^.m nghi~ 
quyen ddo' la ddu?. 
Nhu+~ng nha^.n xe't cu?a chi. ve^` ODB, toi nghi~, la` sa't thu+.c.
ODB khi implemented van du+.a va`o RDB nga^`m o+? duoi ne^n cha^.m
va` te^. ha.i o+? cho^~ khi cha.y  OQL (object sql) thi` chi? co' 
chu'a va` B.Gates mo+'i estimate ddu+o+.c bao nhie^u operation ca^`n 
co' de^? ra duoc kqua? (vo+'i sql thi` ai cu~ng biet truoc ddu+o+.c 
bang va`i phe'p *,/+-). => kho' optimise ho+n (khi CSDL bi. phan tan).
Ca'c norm cho RDB cu~ng kho^ng du`ng duoc de thiet ke cho ODB vv...

Ve^` mo^ hi`nh client-server tu+` xu+a va^~n co' problem, vd cua Tanenbaum
trong quyen Modern OS:
 grep "Hi all" < file1 | sort > file2
chi.u kho^ng viet duoc bang mo hinh client-server.
Dau vay RDB va` C-S model va^~n la`m king va` queen. :-( 

Tho^i tui xin lui, nho+~ ca'c ba'c la`m databases va` networking
thu+' thie^.t ra ne^.n thi` gay :-)

Best!
\Hu`ng