Sorted:

What does Redis transaction mean?

How to handle a large number of concurrent read and write requests in Cassandra?

How can I check the data storage location of Redis?

How to handle the issues of node failure and data recovery in Cassandra?

What types of data does Cassandra support?

What are the replication strategies available in Cassandra?

How can data pagination be implemented in Cassandra?

What is the security mechanism of Cassandra?

What are the steps to setting up a PostgreSQL cluster?

What is the principle of data locality in Hadoop?