Why would you ever want to claim that two select statements on the same table are union-compliant with one another?

2. Use the definition of the join operator and properties of operators o, II, U, p, -, x, prove the formula for the join selectivity. |R DA CS| Join Selectivity |R| * IS

Let R₁ and R₂ be the relations on X={a,b,c}, R₁={ (b,a), (c,b), (a,c) } R₂={ (a,c), (b,c)} R₁-¹= R₂ ° R₁=

Explain the broad definitions of calls and returns using concrete examples.

Give typing answer with explanation and conclusion  Consider the following five transactions:   "butter, bread",   "eggs, bread, milk",   "eggs, bread",   "butter, milk",   "milk, eggs"   Considering all the rules that are generated using arules, what is support value for milk alone?

Based on the provided information below, what would be the entities and the relationship between each one? Thank you!

Discuss the difference between triggers and stored procedures.

Consider these factors while determining the sentinel value you want to use.

Please give some explanation