DESCRIBE Function | Teradata Vantage - DESCRIBE - Analytics Database - Teradata Vantage

Time Series Tables and Operations

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
2023-10-30
dita:mapPath
tuc1628112453431.ditamap
dita:ditavalPath
qkf1628213546010.ditaval
dita:id
sfz1493079039055
lifecycle
latest
Product Category
Teradata Vantageā„¢

Expands the SELECT list with aggregates of value_expression over time. DESCRIBE includes both fully parallel and single-threaded (when using VERBOSE) functions.

To invoke the time series version of this function, use the GROUP BY TIME clause. For more information, see GROUP BY TIME Clause.

Return Value

The return value is defined by each aggregate function that is actually invoked.

Nulls are not included in the result computation.

DISTINCT is not used with MODE when DESCRIBE VERBOSE is expanded.

The following functions are included in the result set of DESCRIBE:
  • MAX
  • MIN
  • AVERAGE
  • STDDEV_SAMP
If using the optional VERBOSE keyword, the list of aggregates also includes:
  • MEDIAN
  • MODE
  • 25th PERCENTILE
  • 50th PERCENTILE
  • 75th PERCENTILE

Additional aggregates included with VERBOSE are single-threaded, and require longer processing times. PERCENTILE computations use a linear process to determine if the percentile lies between two data points. VERBOSE includes MODE, which returns duplicate rows with different values.

The HAVING clause references any aggregates included as part of the DESCRIBE function.

Usage Notes

DESCRIBE has the following restrictions:
  • It can only be used in the SELECT list.
  • It cannot be used in comparisons.
  • It cannot be aliased.
  • It cannot be used as an argument to a function.

value_expression must be a numeric data type.