Quantum Computing for Databases: Overview and Challenges

TL;DR

Quantum databases aim to leverage quantum computing to accelerate data processing, search, and security, while also drawing on quantum-inspired classical methods. The authors survey the landscape, classifying techniques into quantum-enabled technologies and quantum-inspired approaches, and provide a taxonomy of methods across database operations, optimization, security, and transaction management. They discuss representative algorithms—such as Grover's search with $O(\,sqrt{N})$ scaling, and optimization frameworks like QUBO and QAOA—and applications that include join-order optimization and private search, highlighting hardware constraints, encoding challenges, and the need for specialized QPUs. The work outlines open problems and future directions, emphasizing near-term viability on Noisy Intermediate-Scale Quantum devices and the role of quantum-inspired strategies to improve classical databases. Overall, this survey maps the current state and offers a road map toward practical quantum databases and quantum-assisted information retrieval.

Abstract

In the decades, the general field of quantum computing has experienced remarkable progress since its inception. A plethora of researchers not only proposed quantum algorithms showing the power of quantum computing but also constructed the prototype of quantum computers, making it walk into our tangible reality. Those remarkable advancements in quantum computing have opened doors for novel applications, one of which is quantum databases. Researchers are trying to use a paradigm brought by quantum computing to revolutionize various aspects of database management systems. In this paper, we envision the synergy between quantum computing and databases with two perspectives: Quantum computing-enabled technology, and quantum computing-inspired technology. Based on this classification, we present a detailed overview of the research attained in this area, aiming to show the landscape of the field and draw a road map of future directions.

Figures (4)

• Figure 1: An Example of Quantum Circuits
• Figure 2: An Extract of the Chimera Graph Structure
• Figure 3: Quantum circuit representation of Grover's algorithm
• Figure 4: An example of $p$-layer QAOQ