Report prepared for the Experts Meeting Towards the Implementation of a Global Invasive Species
Information Network (GISIN), 6-8 April, 2004. Baltimore, Maryland, USA.
Page 48
8/30/2004
An examination of other databases such as
the Australian National Introduced Marine
Pest Information System (NIMPIS)
(
led to the conclusion that the structure used
for NEMESIS and the NAS database is
quite common.
The question of how these similar
information systems, NEMESIS and
NIMPIS, could be made interoperable
(linked as a distributed system) was then
addressed. A single form was designed to
search the same parameters in multiple
databases and display the combined results
in a single HTML table. This simple
approach is analogous with that of travel
booking Web sites like Expedia or Orbitz,
where customers can compare and select
flights from multiple airline companies
through a single access point. The more
time-consuming alternative of accessing
each airline company’s Web site separately
and repeating the same search for prices,
availability etc. would provide the same
results that are displayed by a single search
on Expedia.
Thus for efficiency’s sake, a DDS appeared
to be the best approach for NIS information
as well. The data that would be searched
would include species lists, fact sheets, and
some collection records. Given the
popularity of XML at the time, it was chosen
as the programming language for
implementing a DDS. The advantage of
using XML is that it makes implementation
of a DDS simple, and it doesn't require
extensive funding or the services of a full
time java programmer, for example.
XML can be used as an object to perform
data-binding and automatic XML-output
functions can be used on some of the
higher end databases. XML can also be
treated as text and used as a very basic
method of generating an HTML table from a
database. The search form passes
parameters to a scripting page, which
generates a query statement to the
database. A connection is made to the
database, a record set matching the search
criteria is retrieved, and for each record a
row in the table is populated with the
corresponding values. The operator then
disconnects from the database. Thus, if an
existing database currently operates by
adding simple XML tags to their data table
(i.e. rather than generating an HTML table)
and places the data within those tags, then
XML is created. The only additional
information needed is the knowledge of how
to create a table in HTML.
NISbase has three tiers of operation. The
first tier is the Web Interface, which is the
user interface. The second tier is the portal
software, which does most of the work, and
the third tier is the various data providers
that are accepting the queries and providing
the data.
Search by
taxonomic group,
common name or
scientific name
Web
Interface
NISbase
Portal
Provider
Websites
USGS
SERC
CSIRO
GSMFC
6.) View Results
1.) Generate
Search
Form from
Server List
1
2.) Select
Servers
and Search
Criteria
2
3.) Pass Request
to Selected
Servers
3
4.) Receive XML
Results
4
5.) Merge &
Format
into HTML
5
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