Question-: Which of the following statements are correct with respect to Apache Cassandra database? A. It uses master slave architecture. B. It uses peer-to-peer communication C. It well integrates with Apache Solr for Analytics D. It uses the De-normalization
Answer: B, D Exp: Apache Cassandra is a NoSQL database with the following feature for fast and optimized query execution on the large volume of data. It uses peer-to-peer communication. Hence, option-1 is out. Yes, it integrates with the Apache Solr but not for the analytics. It’s a tricky option, Solr is a Search solution. Hence, option-3 is not correct. If we want solution for analytics then it should use Apache Spark which also well integrate with the Cassandra. Apache Cassandra does not follow the normalization. However, its Data modeling is similar to relational databases but differ in many key areas for providing blazingly fast interaction. For example, RDBMS uses the joins between tables for relationships, whereas Cassandra uses denormalization to achieve more robust querying. Hence, option-4 is also correct.
Question-: Which of the following is correct with regards to data read/write in/out Cassandra? A. You can use COPY command to read csv data to Cassandra B. You can use COPY command to write CSV data from Cassandra to a file system. C. You can use DUMP command to write CSV data from Cassandra to a file system. D. You can use sstableloader to bulk upload external data to Cassandra. E. You can use COPY command to bulk upload external data to Cassandra. F. You can use DUMP command to bulk upload external data to Cassandra.
Answer: A, B, D Exp: We can use COPY command to read CSV data to DSE and write CSV data from DSE to a file system. Hence, option-1 and 2 both are correct. Similarly, sstableloader provides the ability to bulk load external data into Cassandra Cluster. Hence, option-4 is also correct. We do not have DUMP command. Hence, option 3 and 5 are wrong.
Question-: Which of the following feature helps in Apache Cassandra to help in preventing data loss? A. Each node uses the peer-to-peer gossip communication protocol. B. Commit log C. Memtable D. A,B E. A,B,C
Answer: E Exp: In Apache Cassandra Data loss can be prevented using various features which are below 1. Gossip protocol: Having peer-to-peer distributed system across homogeneous nodes where data is distributed among all nodes in the cluster. And each node frequently exchanges state information about itself and other nodes across the cluster using peer-to-peer gossip communication protocol. 2. Commit Log: A sequentially written commit log on each node captures write activity to ensure data durability. 3. Memtable: Data is indexed and written to an in-memory structure, called a memtable, which resembles a write back cache.