Question-16: Can you please provide some detail or specific properties of the SSTable?
Answer: SSTable has the following property
- SSTable is immutable, once it is created it cannot be modified.
- Cassandra creates new SSTable from the existing SSTable during the compaction process. By merging more than one SSTable
- SSTable is sorted by partition key and primary key index.
- Each table can have multiple SSTable, but same SSTable cannot be shared by any other table.
Question-17: What do you mean by Tombstone record?
Answer: Tombstone are the marker on the records that data would be deleted during next compaction process. As you know, once data is written to the SSTable, it cannot be deleted immediately from the SSTable because SSTables are immutable. As part of next compaction cycle where multiple SSTable data files would be merged and at the same time Tombstone record would be taken care for deletion.
Question-18: Which query language is used to work with Cassandra database?
Answer: To work with the Cassandra database you have to use CQL query language which is very similar to SQL.
Question-19: Is it a good choice or decision to have a single key space for multiple application?
Answer: No, it is recommended that for each application you create a different keyspace. One keyspace can have multiple tables in it.
Question-20: What do you mean by datacenter?
Answer: Datacenter is a group of related nodes which are configured together within cluster, the purpose is to have data replicated across multiple datacenters. Keep in mind that datacenter can be physical or virtual. However, to copy the data across multiple datacenter you have to do some configuration.
