Rules for Writing UDFs that Compress/Decompress LOB Data - Analytics Database - Teradata Vantage

SQL External Routine Programming

Deployment
VantageCloud
VantageCore
Edition
Enterprise
IntelliFlex
VMware
Product
Analytics Database
Teradata Vantage
Release Number
17.20
Published
June 2022
ft:locale
en-US
ft:lastEdition
2025-03-30
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iiv1628111441820.ditamap
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qnu1472247494689
lifecycle
latest
Product Category
Teradata Vantageā„¢
  • The compress UDF must have the following signature:
    • The scalar UDF must declare a single input parameter which has a data type of BLOB, CLOB, or supported distinct LOB-type UDT.
    • The parameter data type and column data type must be the same.
    • The return type must be BLOB.
  • The decompress UDF must have the following signature:
    • The scalar UDF must declare a single BLOB input parameter. The length of the input parameter must be equal to or greater than the length of the BLOB data type returned by the compression UDF.
    • The output of the decompress UDF must be identical to the column type.