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the advantages of no index maintenance, 
immediate data access, and unrestricted use of 
terminology for both data entry and retrieval 
when compared to text DBMSs using an index 
searching method. The time required to fulfill a 
search request using the GESCAN string 
searching text DBMS compares favorably with 
the indexed text DBMSs, especially for complex 
searches. The response time of the GESCAN 
text DBMS is often less than for the indexed text 
DBMSs because GESCAN returns information to 
the user immediately when it is found while, at 
the same time, continuing the search for other 
strings that meet the request. The GESCAN 
hardware/software product reduces the I/O and 
CPU impact on the VAX system while providing 
the text retrieval capability necessary to support 
the EPA GCRP DSI. 
DISCLAIMER 
Mention of trade names or commercial products 
does not constitute endorsement or 
recommendation for use by either NSI 
Technology Services Corporation or the United 
States Environmental Protection Agency. 
REFERENCES 
Barrows, E. H., 1989. Analysis and Integration of 
Ecological Monitoring Data. Proceedings: 
International Symposium on the Design of Water 
Quality Information Systems, Colorado State 
University, Ft. Collins, Colorado, 276-286. 
Hamilton, A., 1989. Picture this. Information 
Center, August, 1989:11-16. 
Schild, K. 1989. Gescan’s text retrieval picks up 
CDA support. Digital Review, October 16, 
1989:25.