Window functions, also known as analytic OLAP functions, have been part of the SQL
standard for more than a decade and are now a widely-used feature. Window functions …

This paper describes enhanced subquery optimizations in Oracle relational database
system. It discusses several techniques--subquery coalescing, subquery removal using …

Digitalization of music has grown deep into people's daily life. Derived services of digital
music, such as recommendation systems and similarity test, then become essential for …

This paper showcases some of the newly introduced parallel execution methods in Oracle
RDBMS. These methods provide highly scalable and adaptive evaluation for the most …

Enterprises are increasingly using Apache Hadoop, more specifically HDFS, as a central
repository for all their data; data coming from various sources, including operational …

Nested queries are commonly used to express complex use-cases by connecting the output
of a subquery as an input to the outer query block. However, their execution is highly time …

The cost of big-data analytics is dominated by shuffle operations that induce multiple disk
reads, writes and network transfers. This paper proposes a new class of optimization rules …

Classical query optimization relies on a predefined set of rewrite rules to re-order and
substitute SQL operators at a logical level. This paper proposes Blitz, a system that can …

Analytical applications, such as exploratory data analysis and decision support, process
complex workloads that include sequences of inter-dependent queries. While modern OLAP …

Analytic functions represent the state-of-the-art way of performing complex data analysis
within a single SQL statement. In particular, an important class of analytic functions that has …