Computer Science > QUESTIONS & ANSWERS > Quiz: Query Optimization _ Consider the relations r1( A, B, C), r2(C, D, E ), and r3( E , F), with p (All)
Quiz: Query Optimization _ Consider the relations r1( A, B, C), r2(C, D, E ), and r3( E , F), with primary keys A, C, and E, respectively. Assume that r1 has 1000 tuples, r2 has 1500 tuples, and r3 has 750 tuples. Estimate the size of r1 ⋈ r2 ⋈ r3, and give an efficient plan for computing the join.
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Consider the relations r1( A, B, C), r2(C, D, E ), and r3( E , F), with primary keys A, C, and E, respectively. Assume that r1 has 1000 tuples, r2 has 1500 tuples, and r3 has 750 tuples. Estimate th ... e size of r1 ⋈ r2 ⋈ r3, and give an efficient plan for computing the join. 2. Consider the following relational schema and SQL query. The schema captures information about employees, departments, and company finances (organized on a per department basis). Emp(eid: integer, did:integer, sal: integer, hobby:char(20)) Dept(did:integer, dname:char(20), floor:integer, phone:char(10)) Finance(did:integer, budget:real, sales: real, expenses:real) Consider the following query: [Show More]
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