U5) NoSQl Flashcards
(19 cards)
What is the difference between RDBMS and XML?
RDBMS stores data in tables; XML represents hierarchical data.
Why is XML considered flexible?
XML is flexible for web services and data exchange.
How can a relational database table row be represented in XML?
A RDB table row can be converted into XML tags.
Which SQL functions help generate XML?
SQL functions like XMLELEMENT, XMLFOREST help generate XML.
Example: SELECT XMLELEMENT(“Employee”, XMLFOREST(emp_id, name, salary)) FROM employees;
What is the XMLType data type in Oracle?
Oracle supports XMLType data type to store, query, and validate XML documents within the DB.
What functions are used with XML in Oracle?
Functions include EXTRACT(), XMLTABLE, XPath expressions.
What are the types of data?
Structured: Tables (RDBMS), Semi-structured: XML, JSON, Unstructured: Images, videos.
What does NoSQL stand for?
NoSQL stands for Not Only SQL, schema-less, high scalability.
What are the types of NoSQL databases?
Types include Key-Value Store (Redis), Document Store (MongoDB), Column Store (Cassandra), Graph DB (Neo4j).
What is the CAP Theorem?
Only 2 of Consistency, Availability, Partition Tolerance can be guaranteed.
What are the BASE properties?
Basically Available, Soft State, Eventually Consistent (vs ACID).
What is the main difference between SQL and NoSQL?
SQL: Structured, vertical scaling, fixed schema; NoSQL: Flexible schema, horizontal scaling.
What is Big Data?
Huge volume, variety, and velocity of data.
Why can’t traditional systems handle big data efficiently?
Traditional systems can’t handle big data efficiently due to its scale.
What are the V’s of Big Data?
Volume, Velocity, Variety, Veracity, Value.
What is Hadoop?
Hadoop is an open-source framework to store and process big data.
What does HDFS do?
HDFS splits files into blocks and distributes them across nodes.
What is the MapReduce process?
Map: Process data in chunks; Reduce: Aggregate results.
What are the components of Hadoop architecture?
Components include HDFS (Storage), MapReduce (Processing), YARN (Resource management).
