Uncompresses the Unicode data that was compressed using the CAMSET function.
the name of the database where the function is located.
Unicode character data that was compressed using the CAMSET function.
Note: This function takes no arguments when used as part of the COMPRESS USING or DECOMPRESS USING phrases. For more information about the COMPRESS/DECOMPRESS phrase, see SQL Data Types and Literals.
This is a Teradata extension to the ANSI SQL:2011 standard.
Argument Type and Rules
Expressions passed to this function must have a data type of VARBYTE(n), where the maximum supported size (n) is 64000.
The input to this function must be the output result of the CAMSET function.
If you specify NULL as input, the function returns NULL.
The result data type is VARCHAR(32000) CHARACTER SET UNICODE.
DECAMSET takes Unicode data that was compressed using the CAMSET function, uncompresses it, and returns an uncompressed Unicode character string as the result.
Although you can call the function directly, DECAMSET is normally used with algorithmic compression (ALC) to uncompress table columns previously compressed with CAMSET.
For more information about ALC, see “COMPRESS and DECOMPRESS Phrases” in SQL Data Types and Literals.
In this example, the Unicode values in the Description column are compressed using the CAMSET function with ALC. The DECAMSET function uncompresses the previously compressed values.
CREATE MULTISET TABLE Pendants
Gem CHAR(10) UPPERCASE CHARACTER SET UNICODE,
Description VARCHAR(1000) CHARACTER SET UNICODE
COMPRESS USING TD_SYSFNLIB.CAMSET
DECOMPRESS USING TD_SYSFNLIB.DECAMSET);