On 2/28/07, Jonah H. Harris <[EMAIL PROTECTED]> wrote:
Last time I checked, Teradata used a modified Fletcher checksum as
well; I wasn't aware of Adler32.


I added adler32 to Gurjeet Singh's crc testing utility, compiled it
with gcc 4.0.0 on a single-core Opteron running FC4, and configured it
for 8K block sizes.

GCC options were -mtune=opteron and the optimizations stated below:

Generic optimization:
test parameters:: SF=1, block_size=8, list_size=1000
Generating data... done. Time taken : 93 milliseconds
Generating CRC using PG (vanilla) algo... done. Time taken : 117 milliseconds
Verifying CRC using PG (vanilla) algo... done. Time taken : 89 milliseconds
Generating CRC using SliceBy8 algo... done. Time taken : 44 milliseconds
Verifying CRC using SliceBy8 algo... done. Time taken : 44 milliseconds
Generating CRC using Adler32 algo... done. Time taken : 52 milliseconds
Verifying CRC using Adler32 algo... done. Time taken : 53 milliseconds

Using -O2
test parameters:: SF=1, block_size=8, list_size=1000
Generating data... done. Time taken : 85 milliseconds
Generating CRC using PG (vanilla) algo... done. Time taken : 31 milliseconds
Verifying CRC using PG (vanilla) algo... done. Time taken : 30 milliseconds
Generating CRC using SliceBy8 algo... done. Time taken : 30 milliseconds
Verifying CRC using SliceBy8 algo... done. Time taken : 30 milliseconds
Generating CRC using Adler32 algo... done. Time taken : 14 milliseconds
Verifying CRC using Adler32 algo... done. Time taken : 14 milliseconds

Using -O3
test parameters:: SF=1, block_size=8, list_size=1000
Generating data... done. Time taken : 87 milliseconds
Generating CRC using PG (vanilla) algo... done. Time taken : 31 milliseconds
Verifying CRC using PG (vanilla) algo... done. Time taken : 31 milliseconds
Generating CRC using SliceBy8 algo... done. Time taken : 30 milliseconds
Verifying CRC using SliceBy8 algo... done. Time taken : 30 milliseconds
Generating CRC using Adler32 algo... done. Time taken : 14 milliseconds
Verifying CRC using Adler32 algo... done. Time taken : 15 milliseconds

Interesting...

--
Jonah H. Harris, Software Architect | phone: 732.331.1324
EnterpriseDB Corporation            | fax: 732.331.1301
33 Wood Ave S, 3rd Floor            | [EMAIL PROTECTED]
Iselin, New Jersey 08830            | http://www.enterprisedb.com/

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