Flexible Operations in Uncertain and Probabilistic Database

Many real world applications need a database that stores probabilistic and uncertain database. Trio is a robust prototype build to store and retrieve uncertain and lineage data. It also supports some features of a relational DBMS. ULDB is an extension of relational databases with expressive construct for representing and manipulating both lineage and uncertainty. ULDB representation is complete and it permits straightforward implementation of many relational operations. Currently Trio performs only select-project-join queries and some set operations. Queries are expressed using TriQL query language. This paper highlights on how multiple aggregation can be handled in select clause in Trio system for uncertain and probabilistic data. It also highlights on how distinct clause can be used along with aggregation function. The results on the implementation of minus and intersect all clause in Trio system have been discussed. These operations allow users to use Trio system in a more flexible way.