What is Cassandra wide-column?

A wide column store is a type of key-value database. It uses tables, rows, and columns, but unlike a relational database, the names and format of the columns can vary from row to row in the same table. In Cassandra all of the rows (in a table) should have a row key then each row key can have multiple columns.

Why Cassandra is called wide column database?

In contrast to a document store, a wide column store is less specialized. A Cassandra wide column store, for example, supports simple numeric and string data types, but it can also use a collection or list as a column data type for storing multiple values or even nested values.

What is wide column data?

A wide-column database is a NoSQL database that organizes data storage into flexible columns that can be spread across multiple servers or database nodes, using multi-dimensional mapping to reference data by column, row, and timestamp.

Is Cassandra wide column or key-value?

Apache Cassandra is a wide column column / column family NoSQL database, and essentially a hybrid between a key-value and a conventional relational database management system.

What is a wide row in Cassandra?

When actual data is stored in column names, we end up with wide rows. Benefits of wide rows: Since column names are stored physically sorted, wide rows enable ordering of data and hence efficient filtering (range scans). You'll still be able to efficiently look up an individual column within a wide row, if needed.

Lesson 3: Cassandra - Cassandra Data Model

What is wide row?

Stand holding a pair of dumbbells in front of your thighs and bend forward at the waist. 2. Pull the dumbbells toward your chest, keeping your arms a little wider than shoulder-width apart. 3. Lower the dumbbells and return to the initial position.

What is wide partition in Cassandra?

Partition in Cassandra represent grouping of similar kind of rows. In Cassandra it is recommended to model your data such that you should have similar kind of rows fall in same partition. This is called wide partition pattern. Searching in Cassandra is super fast using partition key.

What is Cassandra column family?

A Cassandra column family consists of a collection of ordered columns in rows which represent a structured version of the stored data. The keyspace holds these Cassandra column families and each keyspace has at least one column family.

How does Cassandra work?

In Cassandra, the data itself is automatically distributed, with (positive) performance consequences. It accomplishes this using partitions. Each node owns a particular set of tokens, and Cassandra distributes data based on the ranges of these tokens across the cluster.

Is DynamoDB based on Cassandra?

Cassandra and DynamoDB both origin from the same paper: Dynamo: Amazon's Highly Available Key-value store. A chunk of the differences between Cassandra & Dynamo stems from the fact that the data-model of Dynamo is a key-value store. At the same time, Cassandra is designed as a column-family data store.

Is Cassandra columnar database?

Cassandra is an open source, column-oriented database designed to handle large amounts of data across many commodity servers. Unlike a table in a relational database, different rows in the same table (column family) do not have to share the same set of columns.

Is Cassandra a key-value store?

Cassandra is a NoSQL database, which is a key-value store. Some of the features of Cassandra data model are as follows: Data in Cassandra is stored as a set of rows that are organized into tables. Tables are also called column families.

Is DynamoDB wide column?

DynamoDB is a "wide column" style of NoSQL database. While the schema isn't defined beyond the primary key at table construction time, the querying abilities are limited to primary keys or secondary indexes.

What is Cassandra schema?

Overview. Cassandra is a NoSQL database that provides high availability and horizontal scalability without compromising performance. To get the best performance out of Cassandra, we need to carefully design the schema around query patterns specific to the business problem at hand.

Why is Cassandra scalable?

Cassandra is scalable and elastic, allowing the addition of new machines to increase throughput without downtime. When a master node shuts down in databases that operate on the master-slave architecture, the database can't process new writes until a new master is appointed.

Is MongoDB a wide-column store?

Because data doesn't need to fit within the confines of a strict relationship, MongoDB can operate as a general data store.

What is Cassandra good for?

Cassandra's benefits include: Open source: Increases innovation, speed of implementation, flexibility, and extensibility. More cost effective, while avoiding vendor lock-in. Handles a high volume of data with ease: Built to handle a massive amount of data across many servers.

What topology is Cassandra?

Cassandra supports network topology with multiple data centers, multiple racks, and nodes. Cassandra read and write processes ensure fast read and write of data. Cassandra partitions the data in a transparent way by using the hash value of keys.

Is Cassandra structured or unstructured data?

Apache Cassandra™ is a massively scalable open source NoSQL database. Cassandra is perfect for managing large amounts of structured, semi-structured, and unstructured data across multiple datacenters and the cloud.

Is Cassandra a relational database?

RDBMS is a Database management system or software which is designed for relational databases. 2. Cassandra is a NoSQL database. RDBMS uses SQL for querying and maintaining the database.

What is a Cassandra cluster?

A Cassandra cluster is a collection of nodes, or Cassandra instances, visualized as a ring. Cassandra clusters can be defined as “rack aware” or “datacenter aware” so that data replicas could be distributed in a way that could even survive physical outages of underlying infrastructure.

What is clustering key in Cassandra?

The clustering key provides the sort order of the data stored within a partition. All of these keys also uniquely identify the data. We also touched upon the Cassandra architecture and data modeling topics. For more information on Cassandra, visit the DataStax and Apache Cassandra documentation.

What is a static column in Cassandra?

Static column:

In Cassandra Query Language (CQL) it is a special column that is shared by all the rows of a partition. the static column is very useful when we want to share a column with a single value. In Cassandra query language static columns are only static within a given partition.

What do you mean by skinny rows in Cassandra?

Skinny row: has a fixed, relatively small number of column keys. Wide row: has a relatively large number of column keys (hundreds or thousands); this number may increase as new data values are inserted.

What is compaction in Cassandra?

Cassandra Compaction is a process of reconciling various copies of data spread across distinct SSTables. Cassandra performs compaction of SSTables as a background activity. Cassandra has to maintain fewer SSTables and fewer copies of each data row due to compactions improving its read performance.