RENAME FUNCTION (External Form) and Algorithmic Compression - 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
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B035-1184
lifecycle
latest
Product Category
Teradata Vantage™

A RENAME FUNCTION request for a function is only valid if the function is not used by any column across all databases and users for compressing and decompressing its data. This restriction is in place because the column is already compressed using a certain algorithm having stored context and cannot be decompressed if the algorithm name is changed.

Consider the following example. Assume that the algorithmic compression and decompression functions and the table that uses them are created in the order indicated.

     CREATE FUNCTION scsu_comp …;

     CREATE FUNCTION scsu_decomp …;

     CREATE TABLE t1 (
       col1 INTEGER,
       col2 CHAR(10) COMPRESS ('abc', 'efg')
                     COMPRESS USING scsu_comp
                     DECOMPRESS USING scsu_decomp);

Column col2 in table t1 references the algorithmic compression-related UDFs scsu_comp and scsu_decomp for compression and decompression respectively.

After having created table t1, a RENAME FUNCTION request on either scsu_comp or scsu_decomp returns an error to the requestor.