A temporal query system for protocol-directed decision support.
Methods Inf Med
; 33(4): 358-70, 1994 Oct.
Article
em En
| MEDLINE
| ID: mdl-7799812
ABSTRACT
Chronus is a query system that supports temporal extensions to the Structured Query Language (SQL) for relational databases. Although the relational data model can store time-stamped data and can permit simple temporal-comparison operations, it does not provide either a closed or a sufficient algebra for manipulating temporal data. In this paper, we outline an algebra that maintains a consistent relational representation of temporal data and that allows the type of temporal queries needed for protocol-directed decision support. We also discuss how Chronus can translate between our temporal algebra and the relational algebra used for SQL queries. We have applied our system to the task of screening patients for clinical trials. Our results demonstrate that Chronous can express sufficiently all required temporal queries, and that the search time of such queries is similar to that of standard SQL.
Buscar no Google
Base de dados:
MEDLINE
Assunto principal:
Sistemas Inteligentes
/
Protocolos Clínicos
/
Técnicas de Apoio para a Decisão
Tipo de estudo:
Guideline
/
Prognostic_studies
Limite:
Humans
Idioma:
En
Ano de publicação:
1994
Tipo de documento:
Article