🤖 AI Summary
Traditional data preparation methods face limitations in semantic understanding and generalization, struggling to meet the rapidly growing demand for application-ready data. This work systematically reviews the application of large language models (LLMs) in three core tasks—data cleaning, integration, and augmentation—and proposes a task-centered taxonomy that, for the first time, delineates the evolutionary trajectory of LLM-driven data preparation techniques. Through a comprehensive literature review, the study examines key technologies such as prompt engineering, agent-based architectures, and semantic matching, alongside prevailing datasets and evaluation metrics. It highlights LLMs’ strengths in enhancing generalization and semantic comprehension while identifying critical challenges related to computational cost, hallucination, scalability, and the lack of standardized evaluation frameworks. The paper concludes by outlining a roadmap for future research and development in this emerging field.
📝 Abstract
Data preparation aims to denoise raw datasets, uncover cross-dataset relationships, and extract valuable insights from them, which is essential for a wide range of data-centric applications. Driven by (i) rising demands for application-ready data (e.g., for analytics, visualization, decision-making), (ii) increasingly powerful LLM techniques, and (iii) the emergence of infrastructures that facilitate flexible agent construction (e.g., using Databricks Unity Catalog), LLM-enhanced methods are rapidly becoming a transformative and potentially dominant paradigm for data preparation. By investigating hundreds of recent literature works, this paper presents a systematic review of this evolving landscape, focusing on the use of LLM techniques to prepare data for diverse downstream tasks. First, we characterize the fundamental paradigm shift, from rule-based, model-specific pipelines to prompt-driven, context-aware, and agentic preparation workflows. Next, we introduce a task-centric taxonomy that organizes the field into three major tasks: data cleaning (e.g., standardization, error processing, imputation), data integration (e.g., entity matching, schema matching), and data enrichment (e.g., data annotation, profiling). For each task, we survey representative techniques, and highlight their respective strengths (e.g., improved generalization, semantic understanding) and limitations (e.g., the prohibitive cost of scaling LLMs, persistent hallucinations even in advanced agents, the mismatch between advanced methods and weak evaluation). Moreover, we analyze commonly used datasets and evaluation metrics (the empirical part). Finally, we discuss open research challenges and outline a forward-looking roadmap that emphasizes scalable LLM-data systems, principled designs for reliable agentic workflows, and robust evaluation protocols.