ISI-JRF
Two queries equivalent to each other are specified for a relation R(A, B, C, D, E, F). The queries are: πA,B,C(σB>500(R)) σB>500(πA,B,C(R)) The system maintains a B+ tree index for (A, B, C) on R. However, ... the two queries will be preferred by the query optimizer for minimum cost of execution. The cost of query execution is primarily dependent on the number of disk accesses.
Two queries equivalent to each other are specified for a relation R(A, B, C, D, E, F). The queries are: πA,B,C(σB>500(R)) σB>500(πA,B,C(R)) The system maintains a B+ tree index for (A, B, C) on R. However, the index is ... of the two queries will be preferred by the query optimizer for minimum cost of execution. The cost of query execution is primarily dependent on the number of disk accesses.
asked
Apr 19, 2017
in Databases
kauray
233 views