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Abstract |
The importance of the text databases has been increasing. We have developed a general purpose text detabase management system SIGMA, and opened it to the public. SIGMA stores data simply as text files..., Then, each file is regarded as a collection of records if we choose some words and specify them as delimiters. But we often face the cases we have to treat tree structured text data. Gonnet and Tompa (1987) presented an interesting model for such text data, called a p-string data model. Mannila and Räihä (1988) refined this model and discussed its power. In order to realize the data on this model as text files, we put some restrictions on it. We then call this restricted model a t-string model. Various queries are possible on the model by precise and fast one-way sequential processing methods like in SIGMA. We also discuss the connection between our model ancl the relational model already adopted in SIGMA.show more
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