Symbols for Relational Algebra Expressions and Other Symbols…
Symbols for Relational Algebra Expressions and Other Symbols Symbols for relation schemas: R, S, T Symbols for relations: R, S, T, ∅ Symbols for Relational Algebra operators: ∪, -, π, σ, ρ, ⨯, ∩, Δ, ÷, ⨝, ⟗, ⟕, ⟖, ⋉, ⋊, ▷ Symbols for logical connectives: ∧, ∨, ¬ Symbols for comparison predicates: , =, ≤, ≥, ≠ Symbols for set-theoretical operations: ∈, ∉, ⊆, ⊂, ⊇, ⊃ Other mathematical symbols: ⊥, ⋅, ∃, ∀, ∘, ←, → All names (for example, for relations and attributes) should be written in normal font (no italics) to increase readability. All symbols should be surrounded by blanks to increase readability. Database schema Animals(AnimalID, Species, Name, DateOfBirth, Gender, HabitatID, Origin, ArrivalDate, DietType)Habitats(HabitatID, Type, Size, Location, CleaningSchedule, EnvironmentControlSettings)ZooStaff(StaffID, FirstName, LastName, Role, Department, HireDate, Qualifications, ContactNumber)AnimalHealthCare(StaffID, AnimalID, CareDate, Treatment, Notes)VisitorTours(TourID, Date, Time, GuideStaffID, RouteDescription, Theme, Duration, GroupSize)Maintenance(MaintenanceID, HabitatID, Description, Year, Date, StaffID, Status, Priority)ConservationPrograms(ProgramID, Name, Description, StartDate, EndDate, ResponsibleStaffID)ZooEvents(EventID, Name, Date, Time, Location, OrganizerStaffID, TargetAudience, Budget) Query Find the names of staff members who maintained habitats with “Tropical Rainforest” environment control settings last year.
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