Deciding the equivalence of SQL queries is a fundamental problem in data management. As
prior work has mainly focused on studying the theoretical limitations of the problem, very few …

Database-as-a-service offerings enable users to quickly create and deploy complex data
processing pipelines. In practice, these pipelines often exhibit significant overlap of …

Predicate pushdown is a widely adopted query optimization. Existing systems and prior work
mostly use pattern-matching rules to decide when a predicate can be pushed through …

Most work on query optimization has concentrated on loop-free queries. However, data
science and machine learning workloads today typically involve recursive or iterative …

Single-Program-Multiple-Data (SPMD) parallelism has recently been adopted to train large
deep neural networks (DNNs). Few studies have explored its applicability on heterogeneous …

Many data processing systems allow SQL queries that call user-defined functions (UDFs)
written in conventional programming languages. While such SQL extensions provide …

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 …

We present a new technique for automatically synthesizing replacement classes. The
technique starts with an original class O and a potential replacement class R, then uses R to …

Query rewriting is often a prerequisite for effective query optimization, particularly for poorly-
written queries. Prior work on query rewriting has relied on a set of" rules" based on syntactic …

Multilingual data-parallel pipelines, such as Microsoft's Scope and Apache Spark, are widely
used in real-world analytical tasks. While the involvement of multiple languages (often …