ðåôåðàòû ðåôåðàòû
 

Ãëàâíàÿ

Ðàçäåëû

Íîâîñòè

Πñàéòå

Êîíòàêòû

 
ðåôåðàòû

Àâèàöèÿ è êîñìîíàâòèêà
Àäìèíèñòðàòèâíîå ïðàâî
Àðáèòðàæíûé ïðîöåññ
Àðõèòåêòóðà
Àñòðîëîãèÿ
Àñòðîíîìèÿ
Áàíêîâñêîå äåëî
Áåçîïàñíîñòü æèçíåäåÿòåëüíîñòè
Áèçíåñ-ïëàí
Áèîëîãèÿ
Áóõó÷åò óïðàâëåí÷ó÷åò
Âîäîñíàáæåíèå âîäîîòâåäåíèå
Âîåííàÿ êàôåäðà
Ãåîãðàôèÿ è ãåîëîãèÿ
Ãåîäåçèÿ
Ãîñóäàðñòâåííîå ðåãóëèðîâàíèå è íàëîãîîáëîæåíèå
Ãðàæäàíñêîå ïðàâî
Ãðàæäàíñêîå ïðîöåññóàëüíîå ïðàâî
Æèâîòíûå
Æèëèùíîå ïðàâî
Èíîñòðàííûå ÿçûêè è ÿçûêîçíàíèå
Èñòîðèÿ è èñòîðè÷åñêèå ëè÷íîñòè
Êîììóíèêàöèè ñâÿçü öèôðîâûå ïðèáîðû è ðàäèîýëåêòðîíèêà
Êðàåâåäåíèå è ýòíîãðàôèÿ
Êóëèíàðèÿ è ïðîäóêòû ïèòàíèÿ
Êóëüòóðà è èñêóññòâî
Ëèòåðàòóðà
Ëîãèêà
Ëîãèñòèêà
Ìàðêåòèíã
Ìàññ-ìåäèà è ðåêëàìà
Ìàòåìàòèêà
Ìåäèöèíà
Ìåæäóíàðîäíîå è Ðèìñêîå ïðàâî
Óãîëîâíîå ïðàâî óãîëîâíûé ïðîöåññ
Òðóäîâîå ïðàâî
Æóðíàëèñòèêà
Õèìèÿ
Ãåîãðàôèÿ
Èíîñòðàííûå ÿçûêè
Áåç êàòåãîðèè
Ôèçêóëüòóðà è ñïîðò
Ôèëîñîôèÿ
Ôèíàíñû
Ôîòîãðàôèÿ
Õèìèÿ
Õîçÿéñòâåííîå ïðàâî
Öèôðîâûå óñòðîéñòâà
Òàìîæåííàÿ ñèñòåìà
Òåîðèÿ ãîñóäàðñòâà è ïðàâà
Òåîðèÿ îðãàíèçàöèè
Òåïëîòåõíèêà
Òåõíîëîãèÿ
Òîâàðîâåäåíèå
Òðàíñïîðò
Òðóäîâîå ïðàâî
Òóðèçì
Óãîëîâíîå ïðàâî è ïðîöåññ
Óïðàâëåíèå
Ðàäèîýëåêòðîíèêà
Ðåëèãèÿ è ìèôîëîãèÿ
Ðèòîðèêà
Ñîöèîëîãèÿ
Ñòàòèñòèêà
Ñòðàõîâàíèå
Ñòðîèòåëüñòâî
Ñõåìîòåõíèêà
Èñòîðèÿ
Êîìïüþòåðû ÝÂÌ
Êóëüòóðîëîãèÿ
Ñåëüñêîå ëåñíîå õîçÿéñòâî è çåìëåïîëüçîâàíèå
Ñîöèàëüíàÿ ðàáîòà
Ñîöèîëîãèÿ è îáùåñòâîçíàíèå

ðåôåðàòû
ðåôåðàòû

ÍÀÓ×ÍÀß ÁÈÁËÈÎÒÅÊÀ - ÐÅÔÅÐÀÒÛ - Ïðîåêòèðîâàíèå áàçû äàííûõ Äèñïåò÷åðèçàöèÿ àóäèòîðíîãî ôîíäà

Ïðîåêòèðîâàíèå áàçû äàííûõ Äèñïåò÷åðèçàöèÿ àóäèòîðíîãî ôîíäà


                       ÕÀÁÀÐÎÂÑÊÈÉ    ÃÎÑÓÄÀÐÑÒÂÅÍÍÛÉ
                    
ÒÅÕÍÈ×ÅÑÊÈÉ  ÓÍÈÂÅÐÑÈÒÅÒ
  Ãîñóäàðñòâåííûé
Êîìèòåò ÐÔ ïî âûñøåìó îáðàçîâàíèþ.
  Êàôåäðà    ÏΠ
ÂÒ  è  ÀÑ
                           ÊÓÐÑÎÂÀß    ÐÀÁÎÒÀ
                                        ïî  ïðåäìåòó
                                 ÌÎÄÅËÈ
È ÁÀÇÛ ÄÀÍÍÛÕ
                                           íà  òåìó
                
ÏÐÎÅÊÒÈÐÎÂÀÍÈÅ    ÁÀÇÛ  
ÄÀÍÍÛÕ
             «ÄÈÑÏÅÒ×ÅÐÈÇÀÖÈß ÀÓÄÈÒÎÐÍÎÃÎ ÔÎÍÄÀ»
                                      (
1 òèï çàäàíèÿ )
                                                                  âûïîëíèëà
: ñòóäåíòêà ãð. ÏÎ-42
                                                                                  Âåðøêîâà Í.Â
                                                                  ïðîâåðèë
:  ïðåïîäàâàòåëü
                                                                                 
Áàëû÷åâ Á. Â.
 
                                    Õàáàðîâñê,
1997.
                    
ÏÎßÑÍÈÒÅËÜÍÀß ÇÀÏÈÑÊÀ
 Ñîäåðæàíèå ïîÿñíèòåëüíîé çàïèñêè :
             
               I. ÂÂÅÄÅÍÈÅ.
        II. ÎÏÈÑÀÍÈÅ ÈÑÏÎËÜÇÓÅÌÛÕ
ÌÎÄÅËÅÉ ÄÀÍÍÛÕ.
            III. ÄÂÅ ÑÒÐÓÊÒÓÐÛ   ÁÄ. 
                 (â ñîîòâåòñòâèè ñ âûáðàííûìè
ìîäåëÿìè).
            IV. ÑÐÀÂÍÈÒÅËÜÍÛÉ ÀÍÀËÈÇ ÑÒÐÓÊÒÓÐ ÁÄ.
            V. ÎÏÈÑÀÍÈÅ 
ÁÄ  ÑÐÅÄÑÒÂÀÌÈ ÑÓÁÄ   PARADOX.
             VI. ÏÐÈÌÅÐÛ ÎÏÅÐÀÖÈÉ ÍÀÄ
ÝËÅÌÅÍÒÀÌÈ  ÁÄ.
             VII. ÇÀÊËÞ×ÅÍÈÅ.
              VIII. ÑÏÈÑÎÊ ËÈÒÅÐÀÒÓÐÛ.
I. ÂÂÅÄÅÍÈÅ
Â
íàøåì óíèâåðñèòåòå îêîëî 400 àóäèòîðèé èñïîëüçóåìûõ â ó÷åáíîì ïðîöåññå áîëåå
300 ó÷åáíûõ ãðóïï. Êàæäûé ñåìåñòð ñîñòàâëÿåòñÿ
ó÷åáíîå
ðàñïèñàíèå, ïðè ñîñòàâëåíèè êîòîðîãî
ïðèõîäèòñÿ ó÷èòûâàòü
îãðîìíîå
êîëè÷åñòâî ôàêòîðîâ (Ó÷åáíûé ïëàí ,ðàçìåðû
è êîìïîíîâêó ãðóïï, âìåñòèìîñòü è ñïåöèàëèçàöèþ
àóäèòîðèé è ò.ä. è ò.ï).Áåç èñïîëüçîâàíèÿ
ñïåöèàëüíîé
áàçû äàííûõ ýòîò ïðîöåññ ïîãëîùàåò îãðîìíîå êîëè÷åñòâî
ëþäñêèõ
è âðåìåííûõ ðåñóðñîâ, ñîçäàåò îãðîìíîå êîëè÷åñòâî
ðàçëè÷íûõ áóìàã, êîòîðûå â ,ñâîþ î÷åðåäü,  òîæå íàäî ó÷èòûâàòü   ïðè ðàáîòå.  
Äîêóìåíòû
òåðÿþòñÿ, âîçíèêàåò áåäëàì è
áåñòîëêîâùèíà. Ðàñïèñàíèå èñïðàâëÿåòñÿ,
äîïîëíÿåòñÿ äî òåõ ïîð  ïîêà âñå
îêîí÷àòåëüíî íå çàïóòàþòñÿ,
è
òîãäà . . . .
      Âîçíèêàåò Áàçà Äàííûõ äëÿ
Äèñïåò÷åðèçàöèè àóäèòîðíîãî ôîíäà.
   (È, ñîîòâåòñòâåííî, îòïàäàåò áîëüøèíñòâî âûøåïåðå÷èñëåííûõ ïðîáëåì)
Èìåÿ
â ðàñïîðÿæåíèè òàêóþ áàçó äàííûõ, Âû áåç òðóäà ìîæåòå âíîñèòü íîâóþ èíôîðìàöèþ,
êîððåêòèðîâàòü åå è ñîçäàâàòü îò÷åòû.
È ïðè ýòîì Âû
îñâîáîäèòå ñåáÿ îò ìíîãî÷àñîâûõ ïîèñêîâ íåîáõîäèìîãî äîêóìåíòà, îò äîëãîé è
ñëîæíîé êîìïîíîâêè èíôîðìàöèè, è íàêîíåö - îñâîáîäèòå ñâîé øêàô îò îãðîìíûõ êèï
áóìàãè.
Òàêèì
îáðàçîì ìîæíî ñäåëàòü âûâîä, ÷òî òàêàÿ áàçà íóæíà, ïîëåçíà è
ìíîãîôóíêöèîíàëüíà.
ÐÀÇÐÀÁÎÒÊÀ
ÏÐÅÄÌÅÒÍÎÉ ÎÁËÀÑÒÈ.
Äëÿ
ýôôåêòèâíîé ðàáîòû äèñïåò÷åðñêîé íåîáõîäèìî ó÷åñòü ñëåäóþùèå îáúåêòû  â äàííîé ïðåäìåòíîé îáëàñòè :
1)  ôàêóëüòåòû , ñïåöèàëüíîñòè  è ãðóïïû ÂÓÇà,
2)  äèñöèïëèíû, èçó÷àåìûå ãðóïïàìè,
3)  èíôîðìàöèÿ î êàôåäðàõ è
ïðåïîäàâàòåëÿõ,
4)  îáùàÿ èíôîðìàöèÿ îá àóäèòîðèÿõ,
5)  äîïîëíèòåëüíàÿ èíôîðìàöèÿ î
êîìïîíîâêå ãðóïï.
Ïîñëå
àíàëèçà íåîáõîäèìîé â ÁÄ èíôîðìàöèè ìîæíî âûäåëèòü ñëåäóþùèå   òàáëèöû :
I. Ñïðàâî÷íèêè
óñëîâíî-ïîñòîÿííîé èíôîðìàöèè.
 Èíôîðìàöèÿ ýòèõ ñïðàâî÷íèêîâ çàíîñèòñÿ â ÁÄ 1
ðàç.
 Âñëåäñòâèå îíà ìîæåò êîððåêòèðîâàòüñÿ è ïîïîëíÿòüñÿ,
íî ðåàëüíî
 íåîáõîäèìîñòü ïîïîëíåíèÿ è èçìåíåíèÿ ìîæåò
âîçíèêíóòü 1 ðàç â ñåìåñòð  ïåðåä åãî
íà÷àëîì.
 1) Ñïèñîê ôàêóëüòåòîâ - Facult.
  Êîä               
Íàèìåíîâàíèå Èíñòèòóòà      
èíñòèòóòà
 NumFac*                    NameFac
    9(1)                            A45
     1              Èíñòèòóò Èíôîðìàöèîííûõ Òåõíîëîãèé
     2             
Èíñòèòóò Ýêîíîìèêè è Óïðàâëåíèÿ
 2) Ñïèñîê ñïåöèàëüíîñòåé - Special.
 Êîä                 Êîä              Íàèìåíîâàíèå 
Ñïåö-òè           èíñòèòóòà   ñïåöèàëüíîñòè
  Nspec*              NumFac       
NameSpec       
    9(3)                  9(1)             
A3                   
      1                       1                 ÏΠ                  
      2                       1                 ÂÌ                   
      3                       2                 ÔÊ                   
3)
Ñïèñîê ãðóïï - Group.
 Êîä                 
Êîä             
Íàèìåíîâàíèå  Êîë-âî
ãðóïïû             Ñïåö-òè       ãðóïïû                ÷åë.
  Ngroup*             Nspec          
Namegroup           Kol
    9(3)                  9(1)             
A6                        9(2)
      1                       1                 ÏÎ-42                   15
      2                       1                 ÏÎ-41                   15
      3                       2                 BM-41                   20
4) Ðàñïðåäåëåíèå ïî ïîòîêàì - Potokg
Êîä            
         Íîìåð
ãðóïïû                 ïîòîêà
 Ngroup*               
Potok*
   9(2)                         
9(2)
      1                            1
      2                            2
      1                            3
           2                            3
5) Ñïèñîê êàôåäð - Kafedr
Êîä            
            Íàçâàíèå
êàôåäðû                 êàôåäðû
   KK*                       NameK
   9(2)                          A30
      1                       èñòîðèè
      2                       ôèçèêè
      3                       ýëåêòðîíèêè
6)Ñïèñîê
ïðåïîäàâàòåëåé - Prep
Êîä               Êîä                         Ôàìèëèÿ, Èìÿ, Îò÷åñòâî        Ó÷¸íîå
êàôåäðû       ïðåïîäàâàòåëÿ       ïðåïîäàâàòåëÿ                           çâàíèå
 KK                   KPrep*                     NamePrep                                  UchZv
  9(2)                   9(2)                            À40                                         À20           
     3                       1                         Êîâàëåíêî À.À.                      äîöåíò
     2                       1                         Ìèõååíêî À.Í                     
7)
Ñïèñîê äèñöèïëèí êàôåäð - Disc.
Êîä                Êîä                      Íàèìåíîâàíèå
êàôåäðû        äèñöèïëèíû        äèñöèïëèíû
  KK                 KD*                       
 NameDisc
   9(2)                9(2)                            A20
   1                      1                          èñòîðèÿ Ðîññèè
   1                      2                         èñòîðèÿ ðåëèãèè
8)
Âèä Çàíÿòèé -  VidZan
Êîä 
âèäà             Âèä   
çàíÿòèé                çàíÿòèé
   KVid*                       Vid
   9(1)                          A20
      1                     ëåêöèè
      2                     ïðàêòèêè
      3                     ëàáîðàòîðíûå
                             ðàáîòû
9)
Ó÷åáíûé ïëàí - UchPl
     Êîä                
Êîä              Êîä Âèäà          Êîä            Êîëè÷åñòâî
  ãðóïïû           äèñöèïëèíû    
çàíÿòèé   ïðåïîäàâàòåëÿ        ÷àñîâ
   Ngroup*                KD*              
Kvid*           KPrep                    KolCh
     9(3)                 9(1)                   9(1)                 9(2)                      9(3)
      1                       1                       1                     1                         60
      1                       1                       2                     4                         30
                           
10)
Âèä àóäèòîðèè - VidAud
Êîä 
Âèäà           Âèä   
àóäèòîðèè        
àóäèòîðèè
 KVAud*               VAud
   9(1)                      A15
     1                    Ëåêöèîííàÿ
          2                   
Äèñïëåéíûé
                                êëàññ
          3                   Ëàáîðàòîðèÿ
                              
ýëåêòðîíèêè        
11)
Îïèñàíèå Àóäèòîðèé - Auditor
Àóäèòî-     Êîä 
âèäà                 Âìåñòèìîñòü
  ðèÿ            àóäèòîðèè       
  Aud*                KVAud                    Vmest
   A5                   9(1)                            9(3)
   317ï                 1                                 40
   330ï                 2                                 10
12)
×èñëèòåëü/Çíàìåíàòåëü - Ch_Z
Êîä  ×/Ç             ×/Ç   
   ChZ*                 
Ch/Z
   9(1)                      A15
     0                    ×èñëèòåëü
     1                     Çíàìåíàòåëü
     
 13) Àóäèòîðíàÿ íàãðóçêà  - Raspis
   Àóäèòîðèÿ     Äåíü      ×/Ç     ïàðà   ïîòîê   Êîä       Êîä Âèäà   Êîä ïðåïî-
                           íåäåëè                                       äèñ-íû   çàíÿòèé      äàâàòåëÿ
    Aud*               Day*      ChZ*  Para*  
Potok      ND        KVD            Kprep
   A5                      9(1)     9(1)     
D        9(3)        9(2)         9(1)              
9(2)
    317ï                    1          0       1          1            
1              2                     1
    317ï                    1         
0       2          2             1              2                     1
ÎÑÍÎÂÍÛÅ
ÏÎÍßÒÈß È ÎÏÐÅÄÅËÅÍÈß.
Îòíîøåíèå - ñïèñîê-òàáëèöà.
Ñõåìà
îòíîøåíèÿ
- êîíå÷íîå ìíîæåñòâî àòðèáóòîâ, ó÷àñòâóþùèõ â îòíîøåíèè.
Êëþ÷ îòíîøåíèÿ - îäèí èëè íåñêîëüêî
àòðèáóòîâ èç ñõåìû îòíîøåíèÿ,        
                                    çíà÷åíèÿ
êîòîðûõ îäíîçíà÷íî îïðåäåëÿþò êîðòåæ
                                    îòíîøåíèé
è â ñîâîêóïíîñòè îáëàäàþò ñâîéñòâîì
                                   
íåèçáûòî÷íîñòè.
Îãðàíè÷åíèå
öåëîñòíîñòè - ëîãè÷åñêîå îãðàíè÷åíèå, êîòîðîå îïðåäåëÿåò
                                                    êëàññ äîïóñòèìûõ ñîñòîÿíèé ÁÄ.
Áàçà Äàííûõ - ýòî ñîâîêóïíîñòü
âçàèìîñâÿçàííûõ äàííûõ äëÿ íåêîòîðîé
                         ïðåäìåòíîé  îáëàñòè, èñïîëüçóåìûõ îäíèì èëè íåñêîëüêèìè
                         ïðèëîæåíèÿìè  è õðàíÿùèõñÿ ñ ìèíèìàëüíîé èçáûòî÷íîñòüþ.
                                   
II. ÎÏÈÑÀÍÈÅ ÈÑÏÎËÜÇÓÅÌÛÕ ÌÎÄÅËÅÉ ÄÀÍÍÛÕ.
Â
äàííîé ðàáîòå ïðåäñòàâëåíî äâå ðàçëè÷íûõ ìîäåëåé äàííûõ :
1)  ðåëÿöèîííàÿ,
2)  èåðàðõè÷åñêàÿ.
1. Ðåëÿöèîííàÿ ìîäåëü äàííûõ
(ÐÌÄ).
ÐÌÄ - ñîâîêóïíîñòü èçìåíÿåìûõ
âî âðåìåíè, íîðìàëèçîâàííûõ îòíîøåíèé               
             ðàçëè÷íûõ ñòåïåíåé.   Îñíîâíîé îñîáåííîñòüþ ÐÌÄ ÿâëÿåòñÿ õîðîøî
            ôîðìàëèçîâàííîå  ïîíÿòèå ëèíåéíûõ ñïèñêîâ, ïîçâîëÿþùåå
èñïîëüçîâàòü
            äëÿ ëèíåéíûõ ñïèñêîâ ðåëÿöèîííîå
èñ÷èñëåíèå.
Óñëîâíûå
îáîçíà÷åíèÿ
R(<èäåíòèôèêàòîð îòíîøåíèÿ>) - ñõåìà îòíîøåíèÿ,
* - êëþ÷åâîå ïîëå.
Äëÿ
ÐÌÄ âîçüìåì ñèñòåìó òàáëèö, ðàçðàáîòàííûõ â ïóíêòå ÂÂÅÄÅÍÈÅ.
Ðàññìîòðèì
ñõåìû îòíîøåíèé è ôóíêöèîíàëüíûõ çàâèñèìîñòåé â îòíîøåíèÿõ.
Ñõåìû
îòíîøåíèé è ôóíêöèîíàëüíûõ çàâèñèìîñòåé.
1. Îòíîøåíèå  Facult.
     R(Facult)={NumFac, NameFac}.
                         
       
NumFac*     <                       NameFac
                                                >
  Ò. ê. NameFac
ÿâëÿåòñÿ  âîçìîæíûì êëþ÷îì îòíîøåíèÿ,
òî Facult Î 3í. ô.
2. Îòíîøåíèå Special.
     R(Special)={Nspec*, NumFac, NameSpec, Norm}.
                                 NameSpec                         Ò. ê. NameSpec
- ÿâëÿåòñÿ  âîçìîæ-
                                                                                        íûì êëþ÷îì
îòíîøåíèÿ, òî
    NSpec*                NumFac                      
                                                                                     
Special Î 3
í. ô.                                            
3. Îòíîøåíèå Group.
     R(Group)={Ngroup*, Nspec, NameGroup, Kol}.
                               NameGroup                        Ò. ê. NameGroup
- ÿâëÿåòñÿ  âîçìîæ-
                                                                                        íûì êëþ÷îì
îòíîøåíèÿ, òî
   
NGroup*                NSpec                      
                                                                                     
GroupÎ 3
í. ô.
                                     Kol                  
4. Îòíîøåíèå Kafedr.
     R(Kafedr)={KK*, NameK}.
     KK*                   NameK                    Ò. ê. NameK ÿâëÿåòñÿ âîçìîæíûì
                                                                   êëþ÷îì
îòíîøåíèÿ, òî Kafedr Î 3 í. ô.
5. Îòíîøåíèå VidZan.
     R(VidZan)={KVid*, Vid}.
    KVid*                     Vid                    Ò. ê. Vid ÿâëÿåòñÿ âîçìîæíûì
                                                                   êëþ÷îì
îòíîøåíèÿ, òî Disc Î 3 í. ô.
6. Îòíîøåíèå VidAud
     R(VidAud)={KVAud*, VAud}.
    
KVAud*              VAud                    Ò. ê. VAud ÿâëÿåòñÿ âîçìîæíûì
                                                                   êëþ÷îì
îòíîøåíèÿ, òî Disc Î 3 í. ô.
7. Îòíîøåíèå Ch_Z.
     R(Ch_Z)={ChZ*, Ch/Z}.
     ChZ*                   Ch/Z                    Ò. ê. Ch/Z ÿâëÿåòñÿ âîçìîæíûì
                                                                   êëþ÷îì
îòíîøåíèÿ, òî Disc Î 3 í. ô.
8. Îòíîøåíèå  Potokg.
     R(Potokg)={NGroup*, Potok*}.
      
NGroup*           Ò. ê. Â äàííîì îòíîøåíèè
ïðèñóòñòâóþò òîëüêî êëþ÷åâûå
                                ïîëÿ, òî  Sp_Disc Î 3 í. ô.
        Potok*
9. Îòíîøåíèå Raspis.
     R(Raspis)={Aud*, Day*, ChZ*, Para*,
Potok, ND,KVD,KPrep}.
       
Aud*             Potok                  
      
Day*                 ND                  Examins  Î 3 í. ô.
      
ChZ*               KVD
       
Para*             KPrep
10. Îòíîøåíèå  Prep.
     R(Prep)={KK, Kprep*, NamePrep,
UchZv}.                    
                                 NamePrep                              PrepÎ 3
í. ô.
                                                                                
    
    Kprep*                     KK                   
                                                                                    
                                    UchZv                  
11. Îòíîøåíèå Disc.
     R(Disc)={KD*, KK, NameDisc}.
                                 NameDisc                        
                                                                         
        
KD*                    KK                                                   Disc Î 3
í. ô.                                            
12. Îòíîøåíèå  Auditor.
     R(Aud*)={KVAud*, Vmest}.
                           KVAud
   Aud*                                                   Auditor Î 3 í. ô.
                           Vmest
13. Îòíîøåíèå UchPl.
      R(UchPl)={NSpec*, KD*,
Kvid*,Kprep,KolCh}.
       
NSpec*           KPrep                  
        
KD*             KolCh                  UchPl  Î 3 í. ô.
       KVid*              
 
Â
ñèëó òîãî, ÷òî âñå ïðîàíàëèçèðîâàííûå îòíîøåíèÿ ïðèíàäëåæàò  òðåòüåé íîðìàëüíîé ôîðìå, íå âîçíèêàåò
íàäîáíîñòè â íîðìàëèçàöèè îòíîøåíèé.
Îãðàíè÷åíèÿ
öåëîñòíîñòè.
Âñå
òàáëèöû ïðåäñòàâëÿþò ñîáîé òàáëèöû ñ êëþ÷àìè. Ïðè ýòîì, îäíàêî, äëÿ ðÿäà
îòíîøåíèé ìîæíî óêàçàòü âîçìîæíûå êëþ÷è :
Facult   - NameFac,
Special -
NameSpec,
Group - NameGroup
Kafedr  - NameK
VidZan - Vid
VidAud - Vaud
Ch_Z - Ch/Z
Îãðàíè÷åíèÿ
ïî ñóùåñòâîâàíèþ.
Êàðäèíàëüíîå
÷èñëî -
îïðåäåëÿåò ìàêñèìàëüíîå è ìèíèìàëüíîå ÷èñëî
                                        ýëåìåíòîâ ìíîæåñòâà Â, ñâÿçàííûõ ñ îäíèì
ýëåìåíòîì
                                       
ìíîæåñòâà À, è íàîáîðîò.
(NumFac)        (Facult):(Special)         (1,1):(1, ¥)
(NSpec)           (Special):(Group)       
(1,1):(1, ¥)
(NGroup)        
(Group):(Potokg)       (1,):(1,1)
                        (Group):(UchPl)         (1,):(1, 1)
                        (Potokg):(UchPl)       
(1,):(1,1)
(Potok)            (Potokg):(Raspis)        (,1):(1,1)
(KK)
               (Kafedr):(Prep)           (1,1):(1,
¥)
                        (Kafedr):(Disc)            (1,1):(1,) 
                        (Prep):(Disc)               (1,):(1, )
(KPrep)           (Prep):(UchPl)             (1,):(1,1)
                        (Prep):(Raspis)            (1,):(1,1)
                        (UchPl): (Raspis)         (1,1):(1,1)
(KD)                (Disc):(UchPl)             (1,):(0,1)
                        (Prep):(Raspis)            (1,):(0,1)
(Kvid)              (VidZan):(UchPl)        (1,3):(0,1)
                        (VidZan):(Raspis)        (1,3):(0,1)
(KVAud)         (VidAud):(Auditor)      (1,):(1,1)
(Aud)              (Auditor):(Raspis)         (1,):(1,1)
(ChZ)              (Ch_Z):(Raspis)            (1,2):(1,1)
2. Èåðàðõè÷åñêàÿ ìîäåëü
äàííûõ (ÈÌÄ).
ÈÌÄ - êëàññ ñåòåâûõ ìîäåëåé
äàííûõ, â êîòîðîì äîïóñêàþòñÿ òîëüêî
            ñòðóêòóðíûå äèàãðàììû â ôîðìå
óïîðÿäî÷åííîãî äåðåâà.
Ìàêåòû òèïîâ
çàïèñåé äëÿ ÈÌÄ.
0)
 VYZ
- îäíîçàïèñåâàÿ  ñòðóêòóðà.
1)
  Facult
  NameFac
2) Special
  NameSpec
3) Group
  NameGroup  
Kol
4) Potokg
     Potok
5) Kafedr
   NameK
6) Prep
    Kprep*    
NamePrep     UchZv
7) Disc
    ND*     
NameDisc
8) UchPl
    ND*  
KPrep      KolCh
9) Auditor
    Aud*    
Vmest
10) Raspis
    Aud*  
Day* Para*   Potok    ND      
KPrep
Îãðàíè÷åíèÿ  öåëîñòíîñòè.
Îãðàíè÷åíèÿ
ïî ñóùåñòâîâàíèþ :
n
çàïèñè
òèïîâ Raspis, UchPl  ìîãóò ñîäåðæàòü òîëüêî òàêèå çíà÷åíèÿ
     ïîëÿ ND (KPrep), êîòîðûå ïðèñóòñòâóþò â ñîîòâåòñòâóþùåì ïîëå õîòÿ áû
îäíîé   çàïèñè òèïà Disc (Prep).
Äóáëèðîâàíèå
äàííûõ :
Èåðàðõè÷åñêèé
õàðàêòåð ìîäåëè ïðèâåë ê íåîáõîäèìîñòè äóáëèðîâàíèÿ â íåé ÷àñòè äàííûõ :
n êîäîâ äèñöèïëèí ND - â çàïèñÿõ òèïîâ
Disc, Raspis, UchPl.
n
êîäîâ
ïðåïîäàâàòåëåé Kprep - â çàïèñÿõ òèïîâ Prep, UchPl,Raspis.
Èåðàðõè÷åñêèé
êëþ÷ -
ýòî ýëåìåíò äàííûõ, çíà÷åíèÿ êîòîðîãî óíèêàëüíû òîëüêî  íà  òîì èåðàðõè÷åñêîì ïóòè, ãäå îí ïîÿâëÿåòñÿ, íî íå â
ÁÄ                                       
â öåëîì.
Äëÿ
äàííîé ñòðóêòóðû èåðàðõè÷åñêèì êëþ÷îì ÿâëÿåòñÿ ïîëå Aud.
III. ÄÂÅ ÑÒÐÓÊÒÓÐÛ  ÁÄ.   
1.
Ñòðóêòóðà ÁÄ äëÿ ÐÌÄ.
Facult             
Special              Group          Potokg
                                                                    
UchPl
                                               
VidZan
                                                 Prep
Kafedr
                                                 Disc
Auditor                                                        Raspis
VidAud                        ChZ                     
       
1.
Ñòðóêòóðà ÁÄ äëÿ ÈÌÄ.
                                       VYZ
                                                                                                               
Auditor
                                      Facult                   Kafedr
                                   
Special           Prep                 Disc                       Raspis
                                                              
 
                                     Group
     
                                   Potokg              UchPl
 
IV. ÑÐÀÂÍÈÒÅËÜÍÛÉ
ÀÍÀËÈÇ ÏÐÅÄÑÒÀÂËÅÍÍÛÕ ÑÒÐÓÊÒÓÐ.
     
     Êàê 
âèäíî èç ïðåäñòàâëåííûõ îïèñàíèé ìîäåëåé, â ÈÌÄ çàìåòíî ìåíüøå
äóáëèðîâàíèå èíôîðìàöèè. Îäíàêî ÐÌÄ áîëåå íàãëÿäíî ïðåäñòàâëÿåò äàííóþ
ïðåäìåòíóþ îáëàñòü.
 
V.
ÎÏÈÑÀÍÈÅ ÁÄ ÑÐÅÄÑÒÂÀÌÈ  ÑÓÁÄ 
PARADOX.
Íèæå ïðåäñòàâëåíû ñòðóêòóðû òàáëèö Paradox.
VI.
ÏÐÈÌÅÐÛ ÎÏÅÐÀÖÈÉ ÍÀÄ ÝËÅÌÅÍÒÀÌÈ ÁÄ.
Ïîñðåäñòâîì îïåðàöèé ðåëÿöèîííîé àëãåáðû, ñîñòàâèòü
3 çàïðîñà.
1)  Îïðåäåëèòü ðàñïèñàíèå äëÿ
ãðóïïû ÏÎ-42.
(sNameGroup=ÏÎ-42 (Group)Potokg) Raspis = Raspisanie.
2)
 Âûâåñòè ñïèñîê ïðåïîäàâàòåëåé êàôåäðû èñòîðèè.
 
       p{NamePrep}(s NameK=’Èñòîðèÿ’(Kafedr) Prep)=Spisoc   
3)  Âûâåñòè ãðóïïû ñïåöèàëüíîñòè
ÏÎ çàíèìàþùèõñÿ â 220ï.
    D=( p{Ngroup} (sAud=’220ï ’(Raspis)) Potokg)
     Gr= p{Namegroup}(D (sNamespec=’ÏÎ ’(Special)
Group))
I.  ÇÀÊËÞ×ÅÍÈÅ.
     çàêëþ÷åíèå íåîáõîäèìî
äîáàâèòü, ÷òî ðàçðàáîòàííàÿ ÁÄ ìîáèëüíà, íå èçáûòî÷íà, ëåãêî ïîïîëíÿåìà. Îíà,
òàêæå, ìîæåò áûòü óðåçàíà â ñëó÷àå   
íåîáõîäèìîñòè.
II.
  ÑÏÈÑÎÊ ËÈÒÅÐÀÒÓÐÛ.
        Ïðè âûïîëíåíèè ðàáîòû áûëà
èñïîëüçîâàíà ñëåäóþùàÿ ëèòåðàòóðà :
1)  êîíñïåêò ëåêöèé ïî ïðåäìåòó ‘Ìîäåëè è Áàçû Äàííûõ’,
2)  ìåòîäèêà ïî ïðåäìåòó ‘Ìîäåëè è Áàçû Äàííûõ’.
ðåôåðàòû
© ÐÅÔÅÐÀÒÛ, 2012

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