Browsing by Subject "query optimization"

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Access status: Open Access ,
An efficient approach for view selection for data warehouse using tree mining and evolutionary computation
(Wydawnictwa AGH, 2018) Thakare, Atul; Deshpande, Parag
The selection of a proper set of views to materialize plays an important role in database performance. There are many methods of view selection that use different techniques and frameworks to select an efficient set of views for materialization. In this paper, we present a new efficient scalable method for view selection under the given storage constraints using a tree mining approach and evolutionary optimization. The tree mining algorithm is designed to determine the exact frequency of (sub)queries in the historical SQL dataset. The Query Cost model achieves the objective of maximizing the performance benefits from the final view set that is derived from the frequent view set given by the tree mining algorithm. The performance benefit of a query is defined as a function of query frequency, query creation cost, and query maintenance cost. The experimental results show that the proposed method is successful in recommending a solution that is fairly close to an optimal solution.
Access status: Open Access ,
Metody optymalizacji przez indeksowanie dla obiektowego języka zapytań
(Wydawnictwa AGH, 2009) Kowalski, Tomasz Marek; Cebula, Paweł; Kuliberda, Kamil; Wiślicki, Jacek; Adamus, Radosław
In paper we present an overview of query optimization by indexing for SBQL (Stack-Based Query Language). Developed methods have been implemented and tested in ODRA prototype system. The ODRA index implementation is based on linear hashing and works in a scope of a standalone database. It consists of transparent optimization, automatic index updating and management facilities. The semantic equivalence of proposed query optimization methods in the context of object data model and query language is discussed on several examples.
Access status: Restricted ,
Optymalizacja baz danych przestrzennych
(Data obrony: 2012-07-10) Lupa, Michał
Wydział Geologii, Geofizyki i Ochrony Środowiska
The purpose of the thesis was to describe the problem of spatial query optimization. The main topic of the discussion was to develop methods to increase geospatial query performance at the stage of their development. The problem of the order of terms in queries concerning the scope and its impact on performance was also highlighted. In further part of the thesis an overview of the possibilities of indexing spatial data in databases was presented. Transformation of logical formulas was proposed for some kind of queries as a method of optimization. The proposed decomposition of queries was done according to the logic and set theory. The results of the study were the observations in the form of proposed rules of optimization, where the effectiveness was verified experimentally.