full text search and retrieval

[COGITO ERGO SPUD: I THINK, THEREFORE I YAM]

I am lookinig for UNIX full-text search and retrieval programs, preferably 
public domain, but will settle for commercial.  We have several full text 
databases in the 30Megabyte range that we would like to be able to search 
using boolean operators.  What are people out there using?
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Brian McBee  (503)378-4276  brianop at opac.UUCP                
Oregon State Library, State Library Building, Salem, OR 97310
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