Choosing Access Methods (RelOps) (cont)
Example:
- RA operation: Sel[name='John' ∧ age>21](Student)
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Student relation has B-tree index on name
- database engine (obviously) has B-tree search method
giving
tmp[i] := BtreeSearch[name='John'](Student)
tmp[i+1] := LinearSearch[age>21](tmp[i])
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Where possible, use pipelining to avoid storing tmp[i] on disk.
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