A table occupies 3000 blocks. FlightNumber is the primary key. A single-level index on FlightNumber occupies 100 blocks. The WHERE clause of a SELECT specifies "FlightNumber = 3750".What is the maximum number of blocks necessary to process the SELECT with an index scan?
Question
A table occupies 3000 blocks. FlightNumber is the primary key. A single-level index on FlightNumber occupies 100 blocks. The WHERE clause of a SELECT specifies "FlightNumber = 3750".What is the maximum number of blocks necessary to process the SELECT with an index scan?
Solution
To process the SELECT with an index scan, the system would first need to scan the index to find the location of the desired record. Since the index is on the primary key, FlightNumber, this would take a maximum of 100 blocks (the size of the index).
Once the location is found, the system would then need to access the actual record in the table. Since each record is stored in a separate block (as implied by the table occupying 3000 blocks), this would take 1 additional block.
So, the maximum number of blocks necessary to process the SELECT with an index scan would be 100 (for the index scan) + 1 (for accessing the record) = 101 blocks.
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