DoubleCloud glossary

This glossary contains the concepts and technical terms related to DoubleCloud products, managed databases, and cloud computing.

A

Apache Airflow

Apache Airflow® is an open-source platform for developing, scheduling, and monitoring batch-oriented workflows.

To learn more about related terms and concepts, refer to the Apache Airflow® glossary.

Apache Kafka

Apache Kafka® is a distributed event store and stream-processing platform. It’s an open-source system developed by the Apache Software Foundation and written in Java and Scala.

To learn more about related terms and concepts, refer to the Apache Kafka® glossary.

C

CIDR

CIDR (Classless Inter-Domain Routing) is a method of allocating IP addresses for routing. CIDR notation consists of an IP address and a suffix that indicates the number of bits in the prefix, such as 10.0.0.0/16.

CLI

A Command Line Interface or CLI is a text-based user interface for interacting with the operating system or programs running on it. Instead of interacting with graphical elements like buttons or dropdown menus, users type text commands in a terminal or console.

Most of the popular DBMSs have CLI tools to interact with databases. For example, you can connect to Managed ClickHouse® clusters using the ClickHouse Client.

ClickHouse

ClickHouse® is an open-source column-oriented database management system known for its speed and resource efficiency. It can query billions of rows in milliseconds, which makes it the go-to database for real-time analytics.

To learn more about related terms and concepts, refer to the ClickHouse® glossary.

Cluster

A group of one or more database servers or nodes that operate as a single unit. Grouping nodes allows for better scalability, performance, and availability.

O

Object storage

An approach to storing and managing unstructured data as discrete units called objects. Object storage doesn’t have a hierarchy of directories and files. It’s ideal for storing data that’s written only once and then read one or more times.

OLAP

OnLine Analytical Processing (OLAP) is a type of database system designed for analyzing large volumes of data. OLAP databases are optimized for read-intensive operations. Data is usually written once and rarely, if ever, updated or deleted.

OLTP

OnLine Transaction Processing (OLTP) is a type of database system designed to handle real-time record processing, such as payments, health records, or inventory management. OLTP databases are primarily used for write-intensive operations, and data is constantly being inserted, updated, and deleted as transactions are taking place.

P

Port

A logical access point used in network protocols where network connections start and end. Ports are linked to a specific service or process on a device. It allows different processes to use the same connection without interfering.

Different database systems use specific default ports for network communications. For example, PostgreSQL uses 5432 as the default TCP port, and ClickHouse® uses 8443 for HTTPS connections.

Primary key

In relational databases, a primary key is a unique identifier for a record in a database table. Two records can’t have the same primary key, which ensures data integrity as duplicate values can’t be inserted in the table. Primary keys are non-nullable and usually immutable.

In ClickHouse®, however, a primary key serves a different function. Instead of ensuring data uniqueness, primary keys determine how data is stored in tables allowing for fast data retrieval.