Databases on CD-ROM
4 messages in this thread
This thread popped up at a perfect time for me. I have been looking for
someone who has used Xbase with a CD-ROM. I couldn't find anyone who had tried
it, so I had just made arrangements with Kathy Cochrane to burn a prototype for
me when I found this. So it made my day to learn that someone has already been
down this road.
The comment about accessing multiple indexes, etc… sounds like good advice.
Do you have any other suggestions? I have 489,000 records in 420 MB of data,
and have been using Alpha4 to import the records (it has the best data import
tools that I have found). But I'm in the process of changing to FoxPro 2.5
which is about 50% faster searching and indexing than Alpha4.
Have you tried the Extract program which can be downloaded from the Census
Bureau BBS? It appears to be a relatively simple public domain program which
will pull records off of a CD for further crunching with a DBMS or spreadsheet.
BTW, I can get more than 420 MB of .DBF files on one QIC-80 tape cartridge with
compression on. Besides being much easier to work with than 1/2 inch tape, the
cost of tapes and shipping will pay for the 1/4 inch drive pretty fast.
Regards,
John
John (and Jeffrey),
The CD I am starting to work on will probably have Census data on it
— but as I am just beginning this project I don't have much feel for
what this entails. Have you worked with this kind of data in your
projects, and what would be the best way for me to familiarize myself
with it? Could you also post the phone number for the Census BBS?
Thanks mucho
— Samuel
Samuel,
I have not worked with the Census data. But I have downloaded their Extract
software. (Have not yet quite figured out what to do with it though. <g>) The
documentation is a little rough, but the price is right.
The Census BBS number is 301-763-7554 N81 up to 9600, and you might want to
call at night. The extract file, while zipped, is fairly large (about 300K).
Let me know how (if) it works for you. I'm interested in using it for
extracting other .DBF files from CD. But I'm concentrating on FoxPro for now.
Regards,
John
John,
What you want to do with your CD will depend what you ought to have on it. Our
requirement is that we run our programs directly off the CD. We will typically
run reports from Louisiana today, Northern California tomorrow, Maine the next
day, etc. In this kind of environment it is very important that you put all
the files you will need for *both* Alpha4 and FoxPro 2.5 including indexes on
the CD (if you intend to use both these products against your database).
Someone else may want to use the CD as an archive storage medium for big
databases (e.g. STF1 or STF3 from the Census). In that case you want to make
the data as tiny as possible. When you decide to work with a particular set of
records you can "Extract" them. This adds a step to process of generating your
reports. If others will have to use this disc you will need to train them and
document the "extract" step. And the process of specifying records to pull,
running the extract program, and structuring the resulting output into a format
you can use will take some amount of time. In some circumstances these issues
pose no problem. In others they are critical.
Also, for Census data I've found a company that is releasing STF1A and STF3A on
a 4 CD set for $500. The CDs are arranged by region so that all the North
Carolina data, e.g., is on the same CD. At that price I cannot afford to do it
myself!
Jeffrey William Gillette