  Modern real-time business analytic consist of heterogeneous workloads (e.g,
database queries, graph processing, and machine learning). These analytic
applications need programming environments that can capture all aspects of the
constituent workloads (including data models they work on and movement of data
across processing engines). Polystore systems suit such applications; however,
these systems currently execute on CPUs and the slowdown of Moore's Law means
they cannot meet the performance and efficiency requirements of modern
workloads. We envision Polystore++, an architecture to accelerate existing
polystore systems using hardware accelerators (e.g, FPGAs, CGRAs, and GPUs).
Polystore++ systems can achieve high performance at low power by identifying
and offloading components of a polystore system that are amenable to
acceleration using specialized hardware. Building a Polystore++ system is
challenging and introduces new research problems motivated by the use of
hardware accelerators (e.g, optimizing and mapping query plans across
heterogeneous computing units and exploiting hardware pipelining and
parallelism to improve performance). In this paper, we discuss these challenges
in detail and list possible approaches to address these problems.
