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vault backup: 2026-07-22 18:21:36

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Benjamin Neumann
2026-07-22 18:21:36 +02:00
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SS2026/Datenbanken und Informationssysteme/Relationales Datenmodell/Relationales Datenmodell.md
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@@ -30,6 +30,34 @@ Referenziert einen Primärschlüssel einer anderen Tabelle
## Relationale Algebra
[[Relationale Algebra]]
## Relationaler Kalkül
Beschreibt, WAS das Ergebnis erfüllen muss.
### Tupelkalkül
Ergebnis enthält Tupel t für die F(t) wahr ist.
![[Pasted image 20260722181003.png]]
Existenzquantor:
![[Pasted image 20260722181126.png]]
Allquantor:
![[Pasted image 20260722181151.png]]
Ergebnisschema kann neue Tupel konstruieren:
![[Pasted image 20260722181240.png]]
Tupelvariablen:
![[Pasted image 20260722181636.png]]
![[Pasted image 20260722181643.png]]
![[Pasted image 20260722181649.png]]
Semantik:
![[Pasted image 20260722181801.png]]
![[Pasted image 20260722181944.png]]
![[Pasted image 20260722182103.png]]