Deening a view over a semistructured database introduces many new problems. In this paper we propose a view speciication language and consider the problem of answering queries posed over views. The two main approaches, query rewriting and view materialization, are outlined with focus on the diicult problems caused by the semistructured nature of the data.

01 Chapter 1: Introduction 02 Chapter 2: An Overview of Query Processing 04 Chapter 3: DDAG 08 Chapter 4: Distributed Query Optimization 10 Chapter 5: View Materialization using DDAG 11 Chapter 6: View Replacement 16 Chapter 7: Results 17 Chapter 8: Conclusion and Future Work 19 References 20

De ning a view over a semistructured database introduces many new problems. In this paper we propose a view speci cation language and consider the problem of answering queries posed over views. The two main approaches, query rewriting and view materialization, are outlined with focus on the di cult problems caused by the semistructured nature of the data.

The purpose of the paper is operationalization development processes’ concepts in terms threats to a government’s socio-economic system on an example specific threat that currently actively materializing itself – COVID -19. research aims at structuring process threat’s system. It shows negative changes Ukraine’s system, their indicators and consequences inherent last stage materialization stage...

Top-k is the most important query type in OLAP, a common data warehouses model. Recently, OLAP was extended to represent data ambiguity, specifically imprecision and uncertainty. However, how to deal with top-k queries in uncertain OLAP still remains an unanswered question. This project introduces a solution for top-k query evaluation in uncertain OLAP including query semantic definition, query...