Shorter checksum than MD5

Mercuro this at is.invalid
Fri Sep 10 10:51:59 CEST 2004


Paul Rubin wrote:

> Mercuro <this at is.invalid> writes:
> 
>>I have a proprietary system, which I can't modify. But, it uses Foxpro
>>DBF files which I can read. I have found all the data I want to have
>>in a MySQL table. (this table will be used to lookop prices and to
>>find other information about articles)
>>
>>Since I'm not able to put some timestamps on changed records, I got
>>the idea to put a checksum on each record and save it in the MySQL
>>table. Every night I would 'SELECT' all checksums together with the
>>artikelnumbers and than compare it one by one with newly calculated
>>checksums from the DBF file.  Only the changed checksums shall be
>>'UPDATED' and missing numbers would be 'INSERTED'.
> 
> 
> I'm a little confused.  Is only the DBF file getting updated?

the MySQL table should be updated by the DBF file

   If you
> can put a checksum on each record, why can't you put a timestamp on
> each record?

Not in the DBF file, which is immutable for me.

   Or why can't you just migrate all the data from 
the DBF
> into another file every night, and then just scan the file to find the
> changes from the previous night's version?

That I can give a try

> 
> 
>>This is the code I have for now:
>>(I will probably change md5 with crc32)
> 
> 
> Where are the updates coming from?
from a proprietary system, which uses DBF files.
It is updated by modem connection, every day once.



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