Surrogate Keys - Analytics Database - Teradata Vantage

SQL Data Definition Language Detailed Topics

Deployment
VantageCloud
VantageCore
Edition
Enterprise
IntelliFlex
VMware
Product
Analytics Database
Teradata Vantage
Release Number
17.20
Published
June 2022
Language
English (United States)
Last Update
2023-07-11
dita:mapPath
vuk1628111288877.ditamap
dita:ditavalPath
qkf1628213546010.ditaval
dita:id
B035-1184
lifecycle
latest
Product Category
Teradata Vantage™

Situations sometimes occur where the identification and choice of a simple primary key is difficult, if not impossible. There might be no single column that uniquely identifies the rows of a table or there might be performance considerations that argue against using a composite key. In these situations, surrogate keys are an ideal solution.

A surrogate key is an artificial simple key used to identify individual rows uniquely when there is no natural key or when the situation demands a simple key, but no natural non-composite key exists. Surrogate keys do not identify individual rows in a meaningful way: they are simply an arbitrary method to distinguish among them.

Surrogate keys are typically arbitrary system-generated sequential integers. You can generate surrogate keys in the database using the identity column feature (see Identity Columns). To use an identity column to generate surrogate key values, specify the GENERATED ALWAYS and NO CYCLE options and ensure that the data type for the column is either NUMERIC(18,0) or DECIMAL(18,0).