Query optimizer is at the heart of the database systems. Cost-based optimizer studied in this
paper is adopted in almost all current database systems. A cost-based optimizer introduces …

Short‐term traffic forecasting is becoming more important in intelligent transportation
systems. The k‐nearest neighbour (kNN) method is widely used for short‐term traffic …

Statistical models are generally computed outside a DBMS due to their mathematical
complexity. We introduce techniques to efficiently compute fundamental statistical models …

Modern data management applications involve complex processing tasks over large
volumes of data. Although this falls naturally within the scope of relational databases, many …

We present a “black-box” approach to estimating query cardinality that has no knowledge of
query execution plans and data distribution, yet provides accurate estimates. It does so by …

Enterprises are adapting large-scale data processing platforms, such as Hadoop, to gain
actionable insights from their" big data". Query optimization is still an open challenge in this …

Query optimization is a hallmark of database systems enabling complex SQL queries of
today's applications to be run efficiently. The query optimizer often fails to find the best plan …

Query optimization has long been fundamental for database systems. There are cracks in
the edifice, however, as the complexity of modern query workloads outpace what database …

This paper presents a query optimizer module based on cost estimation that chooses the
best filtering step algorithm to perform a specific spatial join operation. A set of expressions …

Delivering accurate estimates of query costs in web services is important in different
contexts, eg, to measure their Quality of Service. However, building a reliable cost model is …