Many forms of static reasoning about program behaviours are known in the literature, yet formal relationships are studied surprisingly infrequently. While most type systems are well-known to be captured by abstract interpretations, the situation for type-and-effect systems is, in the general case, unsettled despite strong hypotheses and occasional framing of effect systems as abstract interpretations. We develop a formal relationship between abs... Read more ›
I just released ed25519-wasm, a small Rust crate for Ed25519 signatures in WebAssembly. The static library can also be directly linked in applications w... Read more ›
Qubot, our internal Copilot-powered analytics agent, allows any GitHub employee to ask questions about our data in plain language. Here's what we learned as we built it. The post appeared first on . Read more ›
The BPF verifier has, in the course of wrestling with the difficult problem of statically analyzing loops, grown special support for many kinds of loops over its history, but its fundamental approach to simple for loops has not changed. When it encounters a loop, it evaluates it, iteration by iteration, until reaching an exit condition — a process that can cause the verifier to mistakenly hit the limit on the number of allowed instructions where a better implementation would not. Eduard Zinge... Read more ›
Vega is a popular declarative language for creating interactive data visualizations. It supports reactive data transformations using its streaming dataflow architecture. Despite its widespread adoption, the exact semantics of Vega is subtle and poorly documented. This leads to incorrect or confusing visualizations and difficult-to-understand error messages. This paper makes two contributions. First, we define a graph-based operational semantics,... Read more ›
Data videos integrate dynamic charts, voice narration, and synchronized animations to communicate data insights as temporal narratives, making them an effective medium for improving data consumption efficiency in the data management lifecycle. However, producing high-quality data videos requires expertise spanning data analysis, narrative design, and video production. Existing approaches fall short: static visualization tools (e.g., BI dashboa... Read more ›
I might have mentioned before that I've been slowly working through the Simple tutorial for building a Sea of Nodes compiler. A lot of it is still sort of going over my head but I've learned a couple of interesting things in the process of working through it that I think I can bring back to a query planning context. One thing I learned from it is that my understanding of Hash Consing was a bit myopic. Or incomplete. I have always thought of hash consing as a way to turn value equality into po... Read more ›
Large-scale software development requires dynamic and multifaceted static code analysis that extends beyond the capabilities of traditional tools. Existing tools like CodeQL lack cross-language analysis capabilities and can be time-consuming and resource-intensive. We present CodeFuse-Query, a data system tailored for large-scale code analysis. First, CodeFuse-Query adopts a Logic-Oriented Computation Design, employing Datalog with a two-tie... Read more ›
Remote and disaggregated memory tiers expand the effective memory capacity of analytical database engines, but they also reshape the cost structure of out-of-memory query processing. When an operator spills beyond local DRAM, moving pages to remote memory incurs both data-transfer time and a fixed round-trip latency per transfer. Classical operator analyses and buffer-allocation heuristics primarily target disk spilling by minimizing total I/O v... Read more ›
GitHub Copilot CLI for Beginners: Learn how to use slash commands to control your terminal AI agent. The post appeared first on . Read more ›
96 May in TigerLand p{ margin:10px 0; padding:0; } table{ border-collapse:collapse; } h1,h2,h3,h4,h5,h6{ display:block; margin:0; padding:0; } img,a img{ border:0; height:auto; outline:none; text-decoration:none; } body,#bodyTable,#bodyCell{ height:100%; margin:0; padding:0; width:100%; } .mcnPreviewText{ display:none !important; } #outlook a{ padding:0; } img{ -ms-interpolation-mode:bicubic; } table{ mso-table-lspace:0pt; mso-table-rspace:0pt; } .ReadMsgBody{ width:100%; } .ExternalClass{ wi... Read more ›
Abstract interpretation provides a principled foundation for constructing sound static analyses through systematic abstraction. A central challenge is synthesizing the best abstract transformers that achieve optimal precision within a given abstract domain. This paper addresses this problem for low-level code modeled with fixed-size bit-vectors. Recent approaches formulate the synthesis task as a multi-objective Optimization Modulo Theories (OMT... Read more ›
PLCopen XML defines two encoding formats for IEC 61131-3 Ladder Diagram programs: a textual encoding using elements, and a graphical encoding that represents rung logic as a directed graph of localId/refLocalId connections. ESBMC-PLC supported the textual format but parsed graphical exports from CONTROLLINO, Beremiz, and OpenPLC Editor into an empty GOTO intermediate representation, causing vacuous verification success. This paper presents Graph... Read more ›
Modern game engines increasingly adopt the Entity Component System (ECS) paradigm as a data-oriented alternative to traditional object-oriented architecture. While ECS promotes modularity and performance through the separation of data and behavior, its practical efficiency depends heavily on the underlying data layout. Despite widespread adoption in frameworks, such as Unity DOTS, Bevy, and Flecs, the semantics of the archetype ECS remain inform... Read more ›
Multi-agent LLM systems share state through memory stores, vector indices, and tool registries. We model such sharing as long-running read-generate-write operations under deterministic-generation semantics -- the regime durable-execution engines enforce by deterministic replay -- and formalize four concurrency anomalies in TLA+: stale-generation, phantom-tool, causal-cascade, and tool-effect reordering, structural analogues of classical isolatio... Read more ›
This work introduces ARES, a platform and open pilot dataset for auditing adaptive social engineering risks in LLM-mediated social decision-making through controlled social games. ARES supports human--human, human--AI, and AI--AI settings, combining configurable game templates, role-conditioned LLM agents, psychology-informed participant profiling, structured interaction trees, and synchronised behavioural and biometric acquisition, filtering, a... Read more ›
Cardinality-estimation (CE) research ranks estimators by q-error, yet it is well known that q-error is an imperfect proxy for query-plan quality. We give a measurement-driven account of when it is a good proxy and when it is not, and why. Modeling plan selection as an argmin over a piecewise-linear cost landscape, we find that plan regret (the cost of the chosen plan relative to the optimal, under true cardinalities) is governed by plan-cost geo... Read more ›
Modelica is a well established cyber-physical modeling language, but many modern engineering workflows, such as optimization, differentiable simulation, scientific machine learning, and system analysis, make use of other environments such as CasADi, JAX, and Julia. Existing infrastructure for Modelica toolchains does not target these languages directly, meaning models must typically be rewritten, or lose important information in the interface. T... Read more ›
Security updates have been issued by AlmaLinux (hplip, kernel, kernel-rt, libpng12, libpng15, libxml2, libxslt, mysql:8.0, mysql:8.4, opencryptoki, openssl, postfix, postgresql:15, rsync, and webkit2gtk3), Debian (asterisk, atril, gsasl, and libreoffice), Fedora (ack, bird, chromium, firefox, ldns, librabbitmq, nextcloud, nss, openslide, perl-Protocol-HTTP2, tig, vorbis-tools, and xen), Mageia (coturn, log4cxx, and python-tornado), SUSE (389-ds, buildah, container-suseconnect, distribution, e... Read more ›
The advent of Large Language Models has catalyzed the emergence of interactive Business Intelligence (BI) systems. Although commercial BI products increasingly adopt semantic layers paired with natural language interfaces, they predominantly rely on manual configurations to define metrics and dimensions. Real-world deployments face critical challenges: (a) frequent JOIN operations degrade the accuracy of SQL generation; (b) wide schemas exacerba... Read more ›