Adriana Prado

Integrating pattern mining in relational databases

Almost a decade ago, Imielinski and Mannila introduced the notion of Inductive Databases to manage KDD applications just as DBMSs successfully manage business applications. The goal is to follow one of the key DBMS paradigms: building optimizing compilers for ad hoc queries. During the past decade, several researchers proposed extensions to the popular relational query language, SQL, in order to express such mining queries. In this paper, we propose a completely different and new approach, which extends the DBMS itself, not the query language, and integrates the mining algorithms into the database query optimizer. To this end, we introduce virtual mining views, which can be queried as if they were traditional relational tables (or views). Every time the database system accesses one of these virtual mining views, a mining algorithm is triggered to materialize all tuples needed to answer the query. We show how this can be done effectively for the popular association rule and frequent set mining problems.

An inductive database system based on virtual mining views

Inductive databases integrate database querying with database mining. In this article, we present an inductive database system that does not rely on a new data mining query language, but on plain SQL. We propose an intuitive and elegant framework based on virtual mining views, which are relational tables that virtually contain the complete output of data mining algorithms executed over a given data table. We show that several types of patterns and models that are implicitly present in the data, such as itemsets, association rules, and decision trees, can be represented and queried with SQL using a unifying framework. As a proof of concept, we illustrate a complete data mining scenario with SQL queries over the mining views, which is executed in our system.

An inductive database prototype based on virtual mining views

We present a prototype of an inductive database. Our system enables the user to query not only the data stored in the database but also generalizations (e.g. rules or trees) over these data through the use of virtual mining views. The mining views are relational tables that virtually contain the complete output of data mining algorithms executed over a given dataset. The prototype implemented into PostgreSQL currently integrates frequent itemset, association rule and decision tree mining. We illustrate the interactive and iterative capabilities of our system with a description of a complete data mining scenario.

A Practical Comparative Study Of Data Mining Query Languages

An important motivation for the development of inductive databases and query languages for data mining is that such an approach will increase the flexibility with which data mining can be performed. By integrating data mining more closely into a database querying framework, separate steps such as data preprocessing, data mining, and postprocessing of the results, can all be handled using one query language. In this chapter, we compare six existing data mining query languages, all extensions of the standard relational query language SQL, from this point of view: how flexible are they with respect to the tasks they can be used for, and how easily can those tasks be performed? We verify whether and how these languages can be used to perform four prototypical data mining tasks in the domain of itemset and association rule mining, and summarize their stronger and weaker points. Besides offering a comparative evaluation of different data mining query languages, this chapter also provides a motivation for a following chapter, where a deeper integration of data mining into databases is proposed, one that does not rely on the development of a new query language, but where the structure of the database itself is extended.

Inductive querying with virtual mining views

In an inductive database, one can not only query the data stored in the database, but also the patterns that are implicitly present in these data. In this chapter, we present an inductive database system in which the query language is traditional SQL. More specifically, we present a system in which the user can query the collection of all possible patterns as if they were stored in traditional relational tables. We show how such tables, or mining views, can be developed for three popular data mining tasks, namely itemset mining, association rule discovery and decision tree learning. To illustrate the interactive and iterative capabilities of our system, we describe a complete data mining scenario that consists in extracting knowledge from real gene expression data, after a pre-processing phase.