I still can't believe this, the more I think about it the less I believe
it but it happened today. I'm currently working for a client that is
having their entire manufacturing and accounting system replaced with a
new Informix based system written by a third party software house. Lots
of data conversion and table loads and file transfers - nothing difficult.
Obviously to make sure to two systems are the same the software house are
running comparison reports. Again nothing special.
But where the software house surpass themselves is in the generation of
the difference reports. To report and correct the data they do the
1 Flat file both tables in their entirety.
2 Use awk to extract the columns they are interested into two more
3 Sort these files into a new set of files
4 grep to the two files together to produce a difference report
5 Use the difference report as the input to another grep to find the
6 Combine the difference lines with the original load file
7 Drop and reload the table
8 Repeat all the above to ensure no rows where missed.
When asked why they did all this I was told it was the only way. But why
not just compare the two tables in Informix I was told by one of the
installation guys that he didn't know you could do that.
Paul Watson # I don't suffer from
WF Software Ltd. # stress, I'm just
Tel. (+44) 1436 674729 # a carrier
Fax. (+44) 1436 678693 #