SQL injection occurs when untrusted input is concatenated into SQL queries. Parameterized queries/prepared statements separate code from data, preventing attackers from modifying query logic.
NoSQL databases like MongoDB and Cassandra are designed for horizontal scaling and flexible schemas, making them ideal for cloud-based big data applications with varying data structures.
3NF eliminates partial and transitive dependencies, making it the standard for practical database design. BCNF is stricter but 3NF is the most commonly implemented normalization form.
GROUP BY groups rows with identical values in specified columns, used with aggregate functions like COUNT(), SUM().
Elasticity allows automatic resource provisioning and de-provisioning based on real-time demand, reducing costs.
A heap (min-heap or max-heap) efficiently supports priority queue operations with O(log n) insertion and deletion.
B-Tree maintains balanced structure ensuring O(log n) search, insert, and delete operations, commonly used in databases.
INNER JOIN returns only the records that have matching values in both tables, filtering out non-matching rows.
AES is the current NIST standard for symmetric encryption with key sizes of 128, 192, or 256 bits. DES is deprecated due to weak key size.
COMMIT saves all changes made during the current transaction to the database permanently. Until COMMIT, changes can be rolled back using ROLLBACK.