3NF removes transitive dependencies where a non-key attribute depends on another non-key attribute. BCNF is stricter but 3NF is the standard answer for eliminating transitive dependencies.

Binary search divides the search space in half with each iteration, resulting in logarithmic time complexity O(log n).

DROP removes the entire table structure and data. DELETE removes only data. TRUNCATE removes data but is faster than DELETE.

Hash collisions occur when two different keys hash to the same table index. Resolution techniques include chaining and open addressing.

Relational databases store structured data in tables. Unstructured data is typically stored in NoSQL or document databases.

ACID properties ensure reliable database transactions: Atomicity (all-or-nothing), Consistency (valid state), Isolation (concurrent independence), Durability (permanent storage).

MongoDB is a NoSQL document database that handles unstructured and semi-structured data efficiently, unlike relational databases like PostgreSQL, Oracle, and MySQL.

ACID properties ensure reliable database transactions: Atomicity (all-or-nothing), Consistency (valid state), Isolation (concurrent independence), and Durability (permanent storage).

INNER JOIN returns only rows with matching values in both tables. LEFT JOIN includes unmatched left table rows, FULL OUTER JOIN includes all rows, and CROSS JOIN produces Cartesian product.

Balanced BSTs (AVL, Red-Black) maintain O(log n) search time by keeping height logarithmic. Unbalanced trees degrade to O(n) in worst case.