CRC32 function - Amazon Redshift

CRC32 function

CRC32 is a function used for error detection. The function uses a CRC32 algorithm to detect changes between source and target data. The CRC32 function converts a variable-length string into an 8-character string that is a text representation of the hexadecimal value of a 32 bit-binary sequence. To detect changes between source and target data, use the CRC32 function on the source data and store the output. Then, use the CRC32 function on the target data and compare that output to the output from the source data. The outputs will be the same if the data was not modified, and the outputs will be different if the data was modified.

Syntax

CRC32(string)

Arguments

string

A CHAR string, a VARCHAR string, or an expression that implicitly evaluates to a CHAR or VARCHAR type.

Return type

The CRC32 function returns an 8-character string that is a text representation of the hexadecimal value of a 32-bit binary sequence. The Amazon Redshift CRC32 function is based on the CRC-32C polynomial.

Examples

To show the 8-bit value for the string Amazon Redshift.

SELECT CRC32('Amazon Redshift'); +----------+ | crc32 | +----------+ | f2726906 | +----------+