TY - GEN

T1 - Speeding up SQL Subqueries via Decoupling of Non-correlated Predicate

AU - Радивончик, Дмитрий

AU - Кузин, Яков Сергеевич

AU - Чижов, Антон Игоревич

AU - Щека, Дмитрий Вадимович

AU - Фирсов, Михаил Александрович

AU - Смирнов, Кирилл Константинович

AU - Чернышев, Георгий Алексеевич

PY - 2026/5/1

Y1 - 2026/5/1

N2 - In this paper, we discuss a novel technique for processing correlated subqueries in SQL. The core idea is to isolate the non-correlated part of the predicate and use it to reduce the number of evaluations of the correlated part. We target a specific class of queries for which we propose a potential rewrite and discuss the conditions under which it is advantageous. Next, we address the evaluation aspects of the proposed rewrites: 1) we describe our approach to adapting the block-based Volcano query processing model, and 2) we discuss the benefits of implementing that technique within a position-enabled column-store with late materialization support. Our evaluation has a quantitative part and a qualitative part. The former focuses on studying the impact of non-correlated predicate selectivity on our technique. The latter identifies the limitations of our approach by comparing it with alternative approaches available in existing systems. Overall, experiments conducted using PosDB (a position-enabled column-store) and PostgreSQL demonstrated that, under suitable conditions, our technique can achieve a 5× improvement.

AB - In this paper, we discuss a novel technique for processing correlated subqueries in SQL. The core idea is to isolate the non-correlated part of the predicate and use it to reduce the number of evaluations of the correlated part. We target a specific class of queries for which we propose a potential rewrite and discuss the conditions under which it is advantageous. Next, we address the evaluation aspects of the proposed rewrites: 1) we describe our approach to adapting the block-based Volcano query processing model, and 2) we discuss the benefits of implementing that technique within a position-enabled column-store with late materialization support. Our evaluation has a quantitative part and a qualitative part. The former focuses on studying the impact of non-correlated predicate selectivity on our technique. The latter identifies the limitations of our approach by comparing it with alternative approaches available in existing systems. Overall, experiments conducted using PosDB (a position-enabled column-store) and PostgreSQL demonstrated that, under suitable conditions, our technique can achieve a 5× improvement.

KW - обработка запросов

KW - обработка подзапросов

KW - поздняя материализация

KW - Query Processing

KW - Column-stores

KW - Subquery Processing

KW - Late Materialization

KW - PosDB

UR - https://link.springer.com/chapter/10.1007/978-3-032-19865-5_13

UR - https://www.scopus.com/authid/detail.uri?authorId=59130664400

UR - https://www.mendeley.com/catalogue/5cbbec08-6623-3944-a775-a4ca0a98ce2e/

U2 - 10.1007/978-3-032-19865-5_13

DO - 10.1007/978-3-032-19865-5_13

M3 - Conference contribution

SN - 978-3-032-19864-8

T3 - Lecture Notes in Computer Science

SP - 160

EP - 167

BT - Model and Data Engineering (MEDI 2025)

PB - Springer Nature

Y2 - 2 November 2025 through 4 November 2025

ER -