File organization (heap, sequential, hashing) in DBMS Theory - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is heap file organization?

Heap file organization stores records in no particular order. New records are added wherever there is free space. It is simple but searching can be slow because records are not sorted.

beginner

How does sequential file organization work?

Sequential file organization stores records one after another in a sorted order based on a key. This makes searching faster for ordered data but inserting new records can be slow because the order must be maintained.

beginner

What is hashing in file organization?

Hashing uses a hash function to calculate the address where a record should be stored. This allows very fast direct access to records but can have collisions that need to be handled.

intermediate

Which file organization is best for fast random access?

Hashing is best for fast random access because it calculates the exact location of a record using a hash function, avoiding the need to search sequentially.

intermediate

What is a disadvantage of sequential file organization?

A disadvantage is that inserting or deleting records can be slow because the file must remain sorted, so records may need to be moved to keep order.

Which file organization stores records without any specific order?

A Indexed

B Sequential

C Hashing

D Heap

Heap file organization stores records in no particular order.

Which file organization is best suited for fast ordered data retrieval?

A Sequential

B Heap

C Hashing

D Clustered

Sequential file organization stores records in sorted order, making ordered retrieval efficient.

What does a hash function do in hashing file organization?

A Calculates the storage address

B Deletes duplicate records

C Sorts the records

D Compresses the file

A hash function calculates the address where a record should be stored for quick access.

Which file organization can have collisions that need special handling?

A Heap

B Hashing

C Sequential

D None

Hashing can have collisions when two records map to the same address.

What is a common drawback of heap file organization?

A Slow insertion

B Needs hash function

C Slow searching

D Requires sorting

Heap file organization can have slow searching because records are unordered.

Explain the main differences between heap, sequential, and hashing file organizations.

Think about how records are stored and accessed in each method.

Describe a real-life scenario where sequential file organization would be preferred over heap or hashing.

Consider situations like a sorted list of customers or transactions.