Terms - Proposals

[Arnold Rots]

The mirror definition needs to be tightened a bit:

A mirror will return, bit for bit, the same result as its parent site
in response to the same query - with one exception: there may be a
time lag in miorror updating, and maybe that should be specified in
the mirror's profile.  I.e.:

A mirror, when presented with a query (or request) Q at time T will
return a bitwise identical response as its parent site would have
returned in response to query Q at time T-dt, where dt should be a
fixed and predictable value (i.e., the time between updates).

What is exempted from this, of course, is meta-metadata, such as the
immediate source of the data and information on the transmission.

  - Arnold

Roy Williams wrote:
> 
> > So a mirror will generally always return the same results as the original. A
> > snapshot can only guarantee to return the same results up until the next
> > update of the original. An extract can never guarantee to return the same
> > results.
> 
> We have astronomical datasets, called A and B.
> 
> A delivers a lossless compression of B. Are they mirrors?
> 
> When I query A and B, I get a table of results. A and B have different default sorting 
> order. Are they mirrors?
> 
> A delivers much lower bandwidth than B. Are they mirrors?
> 
> A delivers data with calibration version 3.2 and B delivers calibration versions 3.1 and 
> 3.2. Are they mirrors?
> 
> A can deliver data from Virgo AND Orion, but B only covers Orion. Are they mirrors?
> 
> A is available all the time, but B is located in Utah and cannot deliver data on Sundays. 
> Are they mirrors?
> 
> A is the server that is mentioned in the peer-reviewed publication by Professor Bigshot. 
> The B data is a copy made by an irresponsible student, and is not mentionsed in the 
> Bigshot paper. Are they mirrors? 
> 
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Arnold H. Rots                                Chandra X-ray Science Center
Smithsonian Astrophysical Observatory                tel:  +1 617 496 7701
60 Garden Street, MS 67                              fax:  +1 617 495 7356
Cambridge, MA 02138                             arots at head.cfa.harvard.edu
USA                                     http://hea-www.harvard.edu/~arots/
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