cassandra developer certification questions - Wikitechy https://www.wikitechy.com/interview-questions/tag/cassandra-developer-certification-questions/ Interview Questions Mon, 13 Sep 2021 11:42:50 +0000 en-US hourly 1 https://wordpress.org/?v=6.9.4 https://www.wikitechy.com/interview-questions/wp-content/uploads/2025/10/cropped-wikitechy-icon-32x32.png cassandra developer certification questions - Wikitechy https://www.wikitechy.com/interview-questions/tag/cassandra-developer-certification-questions/ 32 32 What is the Cassandra coefficient ? https://www.wikitechy.com/interview-questions/cassandra/what-is-the-cassandra-coefficient/ https://www.wikitechy.com/interview-questions/cassandra/what-is-the-cassandra-coefficient/#respond Tue, 13 Jul 2021 05:12:36 +0000 https://www.wikitechy.com/interview-questions/?p=430

Cassandra coefficient:

  • The four components of the Cassandra Coefficient are
    1. The warning, the threat or risk in question,
    2. the decision makers or audience who must react,
    3. The predictor or possible Cassandra, and
    4. The critics who disparage or reject the warning.
  • The Cassandra coefficient is the framework and it offered as a tool and all decision-makers to separate a legitimate warning from a Chicken Little.

There is a lot of commonality amongst actual Cassandras.

  • Technical experts in their field,
  • Very driven by data,
  • First principle/orthogonal thinkers,
  • Have a high sense of personal management, and
  • Many of them had offputting identity / high tension
]]> https://www.wikitechy.com/interview-questions/cassandra/what-is-the-cassandra-coefficient/feed/ 0 What is secondary index in Cassandra ? https://www.wikitechy.com/interview-questions/cassandra/what-is-secondary-index-in-cassandra/ https://www.wikitechy.com/interview-questions/cassandra/what-is-secondary-index-in-cassandra/#respond Tue, 13 Jul 2021 05:03:39 +0000 https://www.wikitechy.com/interview-questions/?p=419

Cassandra secondary index

  • A primary index is global, although a secondary index is local.
  • To query a users by their secondary indexed value or their email every machine has to query its self target of users.
  • One query, five reads from disk.
what is secondary index in cassandra

Using a secondary index

  • Using SQL,after defining a table you can create an index on a column.
  • You can also index a collection column.
  • Secondary indexes are used to query a table using a column that is not general query table.
  • Secondary indexes are difficult to use and can impact performance greatly.
  • The index table is stored on every node in a cluster, so a query involving a secondary index if multiple nodes are accessed it can quickly become a performance nightmare.
  • A general rule of thumb is to index a column with low cardinality of few data.
  • Before creating an index, be aware of when and when not to create an index.
]]> https://www.wikitechy.com/interview-questions/cassandra/what-is-secondary-index-in-cassandra/feed/ 0 What is a seed node in Apache Cassandra ? https://www.wikitechy.com/interview-questions/cassandra/what-is-a-seed-node-in-apache-cassandra/ https://www.wikitechy.com/interview-questions/cassandra/what-is-a-seed-node-in-apache-cassandra/#respond Tue, 13 Jul 2021 04:49:22 +0000 https://www.wikitechy.com/interview-questions/?p=413

Apache Cassandra seed node:

  • Seeds are used to discover the cluster in the start up period.
  • The seed node designation has no purpose other than bootstrapping the gossip process for new nodes joining the cluster.
  • Seed nodes could not be a single point of failure, nor they have do any other purpose in cluster operations except the bootstrapping of nodes.
  • In cluster formation, nodes are verify “join” and each other.
  • However, they do not join any node which respects the protocol.Risks:old partitioned replicas, different clusters, even malicious nodes, so on. So a cluster can be defined by some starting nodes contain at clear addresses and it can be reference for that cluster for any new nodes to join in trust-table way.
  • After some time the seed nodes can go away, then the cluster will keep on.
history of cassandra database
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