VLDB 2026 Research / reviewers in the wild / expert
Chenglong Wang 0005
dblp:94/9817-5
· DBLP profile ↗
25ranked-venue papers
7as first author
17since 2021 · last 2026
0000-0002-5933-6620ORCID · conflict
Domains — the database's venue-derived domains; a paper can count in several
Software engineering, systems software and programming languages · 8 · 3 first-author · 4 since 2021Human-computer interaction and ubiquitous computing · 8 · 2 first-author · 7 since 2021Databases, data management, data science and information retrieval · 4 · 1 first-author · 1 since 2021Artificial intelligence and machine learning · 3 · 3 since 2021Graphics, computer vision, multimedia, augmented reality and games · 2 · 1 first-author · 2 since 2021Theory of computation · 1
| Year | Publication | Venue | Position |
|---|---|---|---|
| 2026 | ReUseIt: Synthesizing Reusable AI Agent Workflows for Web AutomationabstractAI-powered web agents have the potential to automate repetitive tasks, such as form filling, information retrieval, and scheduling, but they struggle to reliably execute these tasks without human intervention, requiring users to provide detailed guidance during every run. We address this limitation by automatically synthesizing reusable workflows from an agent’s successful and failed attempts. These workflows incorporate execution guards that help agents detect and fix errors while keeping users informed of progress and issues. Our approach enables agents to successfully complete repetitive tasks of the same type with minimal user intervention, increasing the success rates from 24.2% to 70.1% across fifteen tasks. To evaluate this approach, we invited nine users and found that our agent helped them complete web tasks with a higher success rate and less guidance compared to two baseline methods, as well as allowed users to easily monitor agent behavior and understand its failures. Misha Sra, Jeevana Priya Inala, Chenglong Wang 0005 |
IUI | 4 |
| 2026 | PiCCL: Data-Driven Composition of Bespoke Pictorial ChartsabstractWe present PiCCL (Pictorial Chart Composition Language), a new language that enables users to easily create pictorial charts using a set of simple operators. To support systematic construction while addressing the main challenge of expressive pictorial chart authoring-manual composition and fine-tuning of visual properties-PiCCL introduces a parametric representation that integrates data-driven chart generation with graphical composition. It also employs a lazy data-binding mechanism that automatically synthesizes charts. PiCCL is grounded in a comprehensive analysis of real-world pictorial chart examples. We describe PiCCL's design and its implementation as piccl.js, a JavaScript-based library. To evaluate PiCCL, we showcase a gallery that demonstrates its expressiveness and report findings from a user study assessing the usability of piccl.js. We conclude with a discussion of PiCCL's limitations and potential, as well as future research directions. Haoyan Shi, Yunhai Wang, Chenglong Wang 0005, Bongshin Lee |
IEEE Trans. Vis. Comput. Graph. | 4 |
| 2025 | Data Formulator 2: Iterative Creation of Data Visualizations, with AI Transforming Data Along the WayabstractFigure 1: With Data Formulator 2, analysts can iterate on a previous design by (1) selecting a chart from data threads and (2) providing combined natural language and graphical user interface inputs in the chart builder to specify the new design.The AI model generates code to transform the data and update the chart.Data threads are updated with new charts for future use. Chenglong Wang 0005, Bongshin Lee, Steven Mark Drucker, Dan Marshall, Jianfeng Gao 0001 |
CHI | 1 |
| 2024 | PhotoScout: Synthesis-Powered Multi-Modal Image SearchabstractDue to the availability of increasingly large amounts of visual data, there is a growing need for tools that can help users find relevant images. While existing tools can perform image retrieval based on similarity or metadata, they fall short in scenarios that necessitate semantic reasoning about the content of the image. This paper explores a new multi-modal image search approach that allows users to conveniently specify and perform semantic image search tasks. With our tool, PhotoScout, the user interactively provides natural language descriptions, positive and negative examples, and object tags to specify their search tasks. Under the hood, PhotoScout is powered by a program synthesis engine that generates visual queries in a domain-specific language and executes the synthesized program to retrieve the desired images. In a study with 25 participants, we observed that PhotoScout allows users to perform image retrieval tasks more accurately and with less manual effort. Celeste Barnaby, Qiaochu Chen, Chenglong Wang 0005, Isil Dillig |
CHI | 3 |
| 2024 | How Do Analysts Understand and Verify AI-Assisted Data Analyses?abstractData analysis is challenging as it requires synthesizing domain knowledge, statistical expertise, and programming skills. Assistants powered by large language models (LLMs), such as ChatGPT, can assist analysts by translating natural language instructions into code. However, AI-assistant responses and analysis code can be misaligned with the analyst’s intent or be seemingly correct but lead to incorrect conclusions. Therefore, validating AI assistance is crucial and challenging. Here, we explore how analysts understand and verify the correctness of AI-generated analyses. To observe analysts in diverse verification approaches, we develop a design probe equipped with natural language explanations, code, visualizations, and interactive data tables with common data operations. Through a qualitative user study (n=22) using this probe, we uncover common behaviors within verification workflows and how analysts’ programming, analysis, and tool backgrounds reflect these behaviors. Additionally, we provide recommendations for analysts and highlight opportunities for designers to improve future AI-assistant experiences. Ken Gu, Ruoxi Shang, Tim Althoff, Chenglong Wang 0005, Steven Mark Drucker |
CHI | 4 |
| 2024 | DynaVis: Dynamically Synthesized UI Widgets for Visualization EditingabstractUsers often rely on GUIs to edit and interact with visualizations — a daunting task due to the large space of editing options. As a result, users are either overwhelmed by a complex UI or constrained by a custom UI with a tailored, fixed subset of options with limited editing flexibility. Natural Language Interfaces (NLIs) are emerging as a feasible alternative for users to specify edits. However, NLIs forgo the advantages of traditional GUI: the ability to explore and repeat edits and see instant visual feedback. Priyan Vaithilingam, Elena L. Glassman, Jeevana Priya Inala, Chenglong Wang 0005 |
CHI | 4 |
| 2024 | Is Self-Repair a Silver Bullet for Code Generation?abstractLarge language models have shown remarkable aptitude in code generation, but still struggle to perform complex tasks. Self-repair---in which the model debugs and repairs its own code---has recently become a popular way to boost performance in these settings. However, despite its increasing popularity, existing studies of self-repair have been limited in scope; in many settings, its efficacy thus remains poorly understood. In this paper, we analyze Code Llama, GPT-3.5 and GPT-4's ability to perform self-repair on problems taken from HumanEval and APPS. We find that when the cost of carrying out repair is taken into account, performance gains are often modest, vary a lot between subsets of the data, and are sometimes not present at all. We hypothesize that this is because self-repair is bottlenecked by the model's ability to provide feedback on its own code; using a stronger model to artificially boost the quality of the feedback, we observe substantially larger performance gains. Similarly, a small-scale study in which we provide GPT-4 with feedback from human participants suggests that even for the strongest models, self-repair still lags far behind what can be achieved with human-level debugging. Theo X. Olausson, Jeevana Priya Inala, Chenglong Wang 0005, Jianfeng Gao 0001, Armando Solar-Lezama |
ICLR | 3 |
| 2024 | Contextualized Data-Wrangling Code Generation in Computational NotebooksabstractData wrangling, the process of preparing raw data for further analysis in computational notebooks, is a crucial yet time-consuming step in data science. Code generation has the potential to automate the data wrangling process to reduce analysts' overhead by translating user intents into executable code. Precisely generating data wrangling code necessitates a comprehensive consideration of the rich context present in notebooks, including textual context, code context and data context. However, notebooks often interleave multiple non-linear analysis tasks into linear sequence of code blocks, where the contextual dependencies are not clearly reflected. Directly training models with source code blocks fails to fully exploit the contexts for accurate wrangling code generation. Junjie Huang 0008, Daya Guo, Chenglong Wang 0005, Jiazhen Gu, Jeevana Priya Inala, Cong Yan, Jianfeng Gao 0001, Nan Duan 0001, Michael R. Lyu |
ASE | 3 |
| 2024 | Data Formulator: AI-Powered Concept-Driven Visualization AuthoringabstractWith most modern visualization tools, authors need to transform their data into tidy formats to create visualizations they want. Because this requires experience with programming or separate data processing tools, data transformation remains a barrier in visualization authoring. To address this challenge, we present a new visualization paradigm, concept binding, that separates high-level visualization intents and low-level data transformation steps, leveraging an AI agent. We realize this paradigm in Data Formulator, an interactive visualization authoring tool. With Data Formulator, authors first define data concepts they plan to visualize using natural languages or examples, and then bind them to visual channels. Data Formulator then dispatches its AI-agent to automatically transform the input data to surface these concepts and generate desired visualizations. When presenting the results (transformed table and output visualizations) from the AI agent, Data Formulator provides feedback to help authors inspect and understand them. A user study with 10 participants shows that participants could learn and use Data Formulator to create visualizations that involve challenging data transformations, and presents interesting future research directions. Chenglong Wang 0005, John Thompson 0002, Bongshin Lee |
IEEE Trans. Vis. Comput. Graph. | 1 |
| 2023 | On the Design of AI-powered Code Assistants for NotebooksabstractAI-powered code assistants, such as Copilot, are quickly becoming a ubiquitous component of contemporary coding contexts. Among these environments, computational notebooks, such as Jupyter, are of particular interest as they provide rich interface affordances that interleave code and output in a manner that allows for both exploratory and presentational work. Despite their popularity, little is known about the appropriate design of code assistants in notebooks. We investigate the potential of code assistants in computational notebooks by creating a design space (reified from a survey of extant tools) and through an interview-design study (with 15 practicing data scientists). Through this work, we identify challenges and opportunities for future systems in this space, such as the value of disambiguation for tasks like data visualization, the potential of tightly scoped domain-specific tools (like linters), and the importance of polite assistants. Andrew M. McNutt, Chenglong Wang 0005, Robert DeLine, Steven Mark Drucker |
CHI | 2 |
| 2023 | Learning Math Reasoning from Self-Sampled Correct and Partially-Correct Solutions
Ansong Ni, Jeevana Priya Inala, Chenglong Wang 0005, Oleksandr Polozov, Christopher Meek, Dragomir R. Radev, Jianfeng Gao 0001 |
ICLR | 3 |
| 2023 | Fast and Reliable Program Synthesis via User InteractionabstractThe performance of programming-by-example systems varies significantly across different tasks and even across different examples in one task. The key issue is that the search space depends on the given examples in a complex way. In particular, scalable synthesizers typically rely on a combination of machine learning to prioritize search order and deduction to prune search space, making it hard to quantitatively reason about how much an example speeds up the search. We propose a novel approach for quantifying the effectiveness of an example at reducing synthesis time. Based on this technique, we devise an algorithm that actively queries the user to obtain additional examples that significantly reduce synthesis time. We evaluate our approach on 30 challenging benchmarks across two different data science domains. Even with ineffective initial user-provided examples for pruning, our approach on average achieves a 6.0× speed-up in synthesis time compared to state-of-the-art synthesizers. Yanju Chen, Chenglong Wang 0005, Xinyu Wang 0006, Osbert Bastani, Yu Feng 0001 |
ASE | 2 |
| 2023 | Towards Auto-Generated Data SystemsabstractAfter decades of progress, database management systems (DBMSs) are now the backbones of many data applications that we interact with on a daily basis. Yet, with the emergence of new data types and hardware, building and optimizing new data systems remain as difficult as the heyday of relational databases. In this paper, we summarize our work towards automating the building and optimization of data systems. Drawing from our own experience, we further argue that any automation technique must address three aspects: user specification, code generation, and result validation. We conclude by discussing a case study using videos data processing, along with opportunities for future research towards designing data systems that are automatically generated. Alvin Cheung, Maaz Bin Safeer Ahmad, Brandon Haynes, Chanwut Kittivorawong, Shadaj Laddad, Chenglong Wang 0005, Cong Yan |
Proc. VLDB Endow. | 7 |
| 2022 | Fault-Aware Neural Code RankersabstractLarge language models (LLMs) have demonstrated an impressive ability to generate code for various programming tasks. In many instances, LLMs can generate a correct program for a task when given numerous trials. Consequently, a recent trend is to do large scale sampling of programs using a model and then filtering/ranking the programs based on the program execution on a small number of known unit tests to select one candidate solution. However, these approaches assume that the unit tests are given and assume the ability to safely execute the generated programs (which can do arbitrary dangerous operations such as file manipulations). Both of the above assumptions are impractical in real-world software development. In this paper, we propose CodeRanker, a neural ranker that can predict the correctness of a sampled program without executing it. Our CodeRanker is fault-aware i.e., it is trained to predict different kinds of execution information such as predicting the exact compile/runtime error type (e.g., an IndexError or a TypeError). We show that CodeRanker can significantly increase the pass@1 accuracy of various code generation models (including Codex, GPT-Neo, GPT-J) on APPS, HumanEval and MBPP datasets. Jeevana Priya Inala, Chenglong Wang 0005, Andrés Codas, Mark Encarnación, Shuvendu K. Lahiri, Madan Musuvathi, Jianfeng Gao 0001 |
NeurIPS | 2 |
| 2022 | Synthesizing analytical SQL queries from computation demonstrationabstractAnalytical SQL is widely used in modern database applications and data analysis. However, its partitioning and grouping operators are challenging for novice users. Unfortunately, programming by example, shown effective on standard SQL, are less attractive because examples for analytical queries are more laborious to solve by hand. Rastislav Bodík, Alvin Cheung, Chenglong Wang 0005 |
PLDI | 4 |
| 2022 | Type-directed synthesis of visualizations from natural language queriesabstractWe propose a new technique based on program synthesis for automatically generating visualizations from natural language queries. Our method parses the natural language query into a refinement type specification using the intents-and-slots paradigm and leverages type-directed synthesis to generate a set of visualization programs that are most likely to meet the user's intent. Our refinement type system captures useful hints present in the natural language query and allows the synthesis algorithm to reject visualizations that violate well-established design guidelines for the input data set. We have implemented our ideas in a tool called Graphy and evaluated it on NLVCorpus, which consists of 3 popular datasets and over 700 real-world natural language queries. Our experiments show that Graphy significantly outperforms state-of-the-art natural language based visualization tools, including transformer and rule-based ones. Qiaochu Chen, Shankara Pailoor, Celeste Barnaby, Abby Criswell, Chenglong Wang 0005, Greg Durrett, Isil Dillig |
Proc. ACM Program. Lang. | 5 |
| 2021 | Falx: Synthesis-Powered Visualization AuthoringabstractModern visualization tools aim to allow data analysts to easily create exploratory visualizations. When the input data layout conforms to the visualization design, users can easily specify visualizations by mapping data columns to visual channels of the design. However, when there is a mismatch between data layout and the design, users need to spend significant effort on data transformation. Chenglong Wang 0005, Yu Feng 0001, Rastislav Bodík, Isil Dillig, Alvin Cheung, Amy J. Ko |
CHI | 1 |
| 2020 | Program Synthesis Using Deduction-Guided Reinforcement LearningabstractIn this paper, we present a new program synthesis algorithm based on reinforcement learning. Given an initial policy (i.e. statistical model) trained off-line, our method uses this policy to guide its search and gradually improves it by leveraging feedback obtained from a deductive reasoning engine. Specifically, we formulate program synthesis as a reinforcement learning problem and propose a new variant of the policy gradient algorithm that can incorporate feedback from a deduction engine into the underlying statistical model. The benefit of this approach is two-fold: First, it combines the power of deductive and statistical reasoning in a unified framework. Second, it leverages deduction not only to prune the search space but also to guide search. We have implemented the proposed approach in a tool called Concord and experimentally evaluate it on synthesis tasks studied in prior work. Our comparison against several baselines and two existing synthesis tools shows the advantages of our proposed approach. In particular, Concord solves 15% more benchmarks compared to Neo, a state-of-the-art synthesis tool, while improving synthesis time by 8.71 $$\times $$ on benchmarks that can be solved by both tools. Yanju Chen, Chenglong Wang 0005, Osbert Bastani, Isil Dillig, Yu Feng 0001 |
CAV (2) | 2 |
| 2020 | Scout: Rapid Exploration of Interface Layout Alternatives through High-Level Design ConstraintsabstractAlthough exploring alternatives is fundamental to creating better interface designs, current processes for creating alternatives are generally manual, limiting the alternatives a designer can explore. We present Scout, a system that helps designers rapidly explore alternatives through mixed-initiative interaction with high-level constraints and design feedback. Prior constraint-based layout systems use low-level spatial constraints and generally produce a single design. Tosupport designer exploration of alternatives, Scout introduces high-level constraints based on design concepts (e.g.,~semantic structure, emphasis, order) and formalizes them into low-level spatial constraints that a solver uses to generate potential layouts. In an evaluation with 18 interface designers, we found that Scout: (1) helps designers create more spatially diverse layouts with similar quality to those created with a baseline tool and (2) can help designers avoid a linear design process and quickly ideate layouts they do not believe they would have thought of on their own. Amanda Swearngin, Chenglong Wang 0005, Alannah Oleson, James Fogarty, Amy J. Ko |
CHI | 2 |
| 2020 | Visualization by exampleabstractWhile visualizations play a crucial role in gaining insights from data, generating useful visualizations from a complex dataset is far from an easy task. In particular, besides understanding the functionality provided by existing visualization libraries, generating the desired visualization also requires reshaping and aggregating the underlying data as well as composing different visual elements to achieve the intended visual narrative. This paper aims to simplify visualization tasks by automatically synthesizing the required program from simple visual sketches provided by the user. Specifically, given an input data set and a visual sketch that demonstrates how to visualize a very small subset of this data, our technique automatically generates a program that can be used to visualize the entire data set. From a program synthesis perspective, automating visualization tasks poses several challenges that are not addressed by prior techniques. First, because many visualization tasks require data wrangling in addition to generating plots from a given table, we need to decompose the end-to-end synthesis task into two separate sub-problems. Second, because the intermediate specification that results from the decomposition is necessarily imprecise, this makes the data wrangling task particularly challenging in our context. In this paper, we address these problems by developing a new compositional visualization-by-example technique that (a) decomposes the end-to-end task into two different synthesis problems over different DSLs and (b) leverages bi-directional program analysis to deal with the complexity that arises from having an imprecise intermediate specification. We have implemented our visualization-by-example approach in a tool called Viser and evaluate it on over 80 visualization tasks collected from on-line forums and tutorials. Viser can solve 84 of these benchmarks within a 600 second time limit, and, for those tasks that can be solved, the desired visualization is among the top-5 generated by Viser in 70% of the cases. Chenglong Wang 0005, Yu Feng 0001, Rastislav Bodík, Alvin Cheung, Isil Dillig |
Proc. ACM Program. Lang. | 1 |
| 2018 | Speeding up symbolic reasoning for relational queriesabstractThe ability to reason about relational queries plays an important role across many types of database applications, such as test data generation, query equivalence checking, and computer-assisted query authoring. Unfortunately, symbolic reasoning about relational queries can be challenging because relational tables are multisets (bags) of tuples, and the underlying languages, such as SQL, can introduce complex computation among tuples. We propose a space refinement algorithm that soundly reduces the space of tables such applications need to consider. The refinement procedure, independent of the specific dataset application, uses the abstract semantics of the query language to exploit the provenance of tuples in the query output to prune the search space. We implemented the refinement algorithm and evaluated it on SQL using three reasoning tasks: bounded query equivalence checking, test generation for applications that manipulate relational data, and concolic testing of database applications. Using real world benchmarks, we show that our refinement algorithm significantly speeds up (up to 100×) the SQL solver when reasoning about a large class of challenging SQL queries, such as those with aggregations. Chenglong Wang 0005, Alvin Cheung, Rastislav Bodík |
Proc. ACM Program. Lang. | 1 |
| 2017 | Cosette: An Automated Prover for SQL
Shumo Chu, Chenglong Wang 0005, Konstantin Weitz, Alvin Cheung |
CIDR | 2 |
| 2017 | Synthesizing highly expressive SQL queries from input-output examplesabstractSQL is the de facto language for manipulating relational data. Though powerful, many users find it difficult to write SQL queries due to highly expressive constructs. Chenglong Wang 0005, Alvin Cheung, Rastislav Bodík |
PLDI | 1 |
| 2017 | Demonstration of the Cosette Automated SQL ProverabstractIn this demonstration, we showcase COSETTE, the first automated prover for determining the equivalences of SQL queries. Despite theoretical limitations, COSETTE leverages recent advances in both automated constraint solving and interactive theorem proving to decide the equivalences of a wide range of real world queries, including complex rewrite rules from the database literature. COSETTE can also validate the inequality of queries by finding counter examples, i.e., database instances which, when executed on the two queries, will return different results. COSETTE can find counter examples of many real world inequivalent queries including a number of real-world optimizer bugs. We showcase three representative applications of COSETTE: proving a query rewrite rule from magic set rewrite, finding counter examples from the infamous optimizer bug, and an interactive visualization of automated grading results powered by COSETTE, where COSETTE is used to check the equivalence of students' answers to the standard solution. For the demo, the audience can experience through the three applications, and explore the COSETTE by interacting with the tool using an easy-to-use web interface. Shumo Chu, Chenglong Wang 0005, Alvin Cheung, Dan Suciu |
SIGMOD Conference | 3 |
| 2017 | Interactive Query Synthesis from Input-Output ExamplesabstractThis demo showcases Scythe, a novel query-by-example system that can synthesize expressive SQL queries from input-output examples. Scythe is designed to help end-users program SQL and explore data simply using input-output examples. From a web-browser, users can obtain SQL queries with Scythe in an automated, interactive fashion: from a provided example, Scythe synthesizes SQL queries and resolves ambiguities via conversations with the users. Chenglong Wang 0005, Alvin Cheung, Rastislav Bodík |
SIGMOD Conference | 1 |