Physical Architecture

Vertica's physical architecture is designed to distribute physical storage and and to allow parallel query execution over a potentially large collection of computing resources.

Terminology

The most important terms to understand are host, instance, node, cluster, and database:

Host
A host is a computer system with a 32-bit or 64-bit Intel or AMD processor, RAM, hard disk, and TCP/IP network interface (IP address and hostname). Hosts share neither disk space nor main memory with each other.
Instance
An instance of Vertica consists of the running Vertica process and disk storage (catalog and data) on a host. There can be only one instance of Vertica running on a host at any time.
Node
A node is a host configured to run an instance of Vertica. It is a member of a database cluster (see Node Definition). For a database to have the ability to recover from the failure of a node requires at least three nodes. Vertica Systems, Inc. recommends that you use a minimum of four nodes. A cluster generally refers a collection of hosts or a collection of nodes bound to a database. A cluster is not part of a database definition and thus does not have a name. An instance of Vertica consists of the running Vertica process and disk storage (catalog and data) on a host. There can be only one instance of Vertica running on a host at any time.
Cluster
A cluster generally refers a collection of hosts or a collection of nodes bound to a database. A cluster is not part of a database definition and thus does not have a name.
Database
A database is a cluster of nodes that, when active, can perform distributed data storage and SQL statement execution through administrative, interactive, and programmatic user interfaces. A cluster generally refers a collection of hosts or a collection of nodes bound to a database. A cluster is not part of a database definition and thus does not have a name.