Use the standard hashing algorithm on the CONNX client and server in almost all circumstances.
If your older mainframe system uses too many CPU cycles running DataSync, contact Technical Support and if it is appropriate, we will help you change your hashing routine.
Caution: Do not adjust or change this setting unless instructed to by a CONNX Technical Support representative.
To enable the selection of the hash function for incremental updates, enter one of the following value:
0 = fnv hash routing (default)
If CNXHASH is set to 0, or the configuration setting for HASH is 0, then the Fowler / Noll / Vo (FNV) Hash is chosen. Here is a description of the algorithm:
http://www.isthe.com/chongo/tech/comp/fnv/
1 = oy_djb 64bit hash routine
If CNXHASH is set to 1, or the configuration setting for HASH is 1, then the Ozan Yigit (SDBM) Hash combined with the Daniel J. Bernstein Hash is chosen. Here is a description of the algorithm:
http://www.cse.yorku.ca/~oz/hash.html
2 = bj 64bit hash routine
If CNXHASH is set to 2, or the configuration setting for HASH is 2, then the Bob Jenkins Hash is chosen. Here is a description of the algorithm:
http://www.cse.yorku.ca/~oz/hash.html
3 = oy 32bit hash routine
If CNXHASH is set to 3, or the configuration setting for HASH is 3, then the Ozan Yigit (SDBM) Hash is chosen. Here is a description of the algorithm:
http://www.cse.yorku.ca/~oz/hash.html
4 = djb 32bit hash routine
If CNXHASH is set to 4, or the configuration setting for HASH is 4, then the Daniel J. Bernstein Hash is chosen. Here is a description of the algorithm:
http://www.cse.yorku.ca/~oz/hash.html
5 = returns zero
If CNXHASH is set to 5, or the configuration setting for HASH is 5, then the NULL is chosen. The NULL hash does nothing and returns zero. It is for benchmarking purposes only and cannot be used for any other purpose.
6 = oy_djb 32bit + djb 32bit hash routine
If CNXHASH is set to 6, or the configuration setting for HASH is 6, then an alternate form of the Ozan Yigit (SDBM) Hash combined with the Daniel J. Bernstein Hash is chosen. Here is a description of the algorithm:
http://www.cse.yorku.ca/~oz/hash.html
7 = u_mac 64bit hash routine
If CNXHASH is set to 7, or the configuration setting for HASH is 7, then the UMAC Hash is chosen if the server is NOT a VAX. Here is a description of the algorithm:
If the server is a VAX, then the program will fire an assert() and stop if data synchronizations are attempted.
If performing data synchronization using CNXHASH and HASH, the hash algorithm used by both client and server must match, or a full synchronization is performed for every sync operation.
Environments: Server, Windows, Unix, VMS, Mainframe
Windows Environment Variable: CNXHASH
Unix Environment Variable: CNXHASH
VMS Logical: CNXHASH
Started Task: CNXHASH
CICS: CNXHASH