trudel@caip.rutgers.edu (Jonathan D. Trudel) (08/16/89)
>...poof ready to roll CD disks. But for data disks you >have to set up the data, index it in some way. This requires that you >have access to all of it, and be able to change it, and that means a >500Mb magnetic disk that could "pretend" it was a CD until you were >ready to master it. With current SCSI technology you can do this for >under $3K, it used to be you needed a mini like a Sun or VAX to just >handle the data. Of course once you get all the data together the >indexing process can be slow at best. Define slow for me. I saw such a system set up on an IBM pc that my girlfriend's friend's husband was working on for a company down in the DC area (I don't remember the name of the company) and they are offering such a product as the one you describe. They are putting governmental records onto an optical disk and getting really reasonable data recovery from it. Considering that it replaces the previous microfiche technology, the access time is greatly improved. The only slowdown occurs for printing - normal photocopy processes are an order of magnitude faster than laser printing... >For hypertext like applications >you want to make sure related information is on physically "near" tracks >and the index stuff has to be pretty well filled in to make the disk >useful. >--Chuck McManis I think that for many data retrieval applications that the access time I saw in such a system was within reason. GRanted, we work with high-speed computers all day long, but many people don't, and are willing to put up with what we might perceive as slowness. But then again, isn't that what people said about computers 20 or 30 years ago? Jon
cmcmanis%pepper@Sun.COM (Chuck McManis) (08/16/89)
In a previous article (Jonathan D. Trudel) writes:
->Define slow for me. I saw such a system set up on an IBM pc that
->my girlfriend's friend's husband was working on for a company down in
->the DC area (I don't remember the name of the company) and they are
->offering such a product as the one you describe. They are putting
->governmental records onto an optical disk and getting really reasonable
->data recovery from it. Considering that it replaces the previous
->microfiche technology, the access time is greatly improved. The only
->slowdown occurs for printing - normal photocopy processes are an order
->of magnitude faster than laser printing...
Ok, my comment was that building the index was "slow", an operating CD
ROM system is certainly "fast" by most definitions. Using your example,
how are the records indexed? If they are simple keys like last names,
or days of the week then you can build the index algorithmically and
fairly quickly. If they are based on things like "All references to
the FUJI project that involved funding decisions" which is the type of
query one might like to make of the congressional record, someone has
to read all of the text and make those connections manually. When an
index is built that way, it can take months or years to do. Similarly,
if you collected a whole bunch of stuff that was externally related like
all of the Fish Disks, you get one index for free "find by VOlume #"
but have to manually build the "find all demos, find all editors, etc"
indexes by hand. Once these indexes have been built and the CD has been
mastered, and a production CD is available. *Using* the data is very
quick and convienient.
->I think that for many data retrieval applications that the access time I
->saw in such a system was within reason. GRanted, we work with
->high-speed computers all day long, but many people don't, and are
->willing to put up with what we might perceive as slowness. But then
->again, isn't that what people said about computers 20 or 30 years ago?
For systems where you are watching an animation and the outcome of the
animation is dependent on which parameters you set, the several possible
outcomes need to be physically close because they must be recalled and
decompressed in less that the time between when the first one was started
and when it finishes. For just getting records, retrieval times on the
order of 1 second aren't bad at all.
--Chuck McManis
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