14 papers
The Decode-Work Law: Margin-Governed, Provably-Exact Spatial Joins over Compressed Geometry
Madhulatha Mandarapu, Sandeep Kunkunuru
Filter-and-refine spatial joins have always avoided touching exact geometry for certified candidate pairs, but the field never modeled the decompression cost of the pairs that surv…
When to Repair a Graph ANN Index: A Matched-Budget Negative Result, and the Interpolated-Baseline Trap That Hid It
Madhulatha Mandarapu, Sandeep Kunkunuru
Graph approximate-nearest-neighbor (ANN) indexes (HNSW, DiskANN/Vamana) lose recall under insert/delete churn, because deletions orphan the greedy-search paths that route through r…
Knowledge Graphs as the Missing Data Layer for LLM-Based Industrial Asset Operations
Madhulatha Mandarapu, Sandeep Kunkunuru
LLM-based agents for industrial asset operations show limited accuracy when reasoning over flat document stores. AssetOpsBench (KDD 2026) establishes that GPT-4 agents achieve 65%…
One Index for Subsumption and Roll-up across Time, Geography, and Ontology
Madhulatha Mandarapu, Sandeep Kunkunuru
Time-series, geospatial, and ontology systems each maintain a hierarchy -- day <= month <= year, zip <= city, is-a / part-of -- and each indexes it in a separate silo. We observe t…
Knowledge-Graph Grounding Helps LLMs Only for Out-of-Training Knowledge: A Controlled Study on Clinical Question Answering
Madhulatha Mandarapu, Sandeep Kunkunuru
A recent Nature Medicine study reports that general-purpose frontier LLMs outperform specialized retrieval-augmented clinical tools on medical benchmarks, and that retrieval can hu…
When Is a Columnar Scan Bandwidth-Bound? A Decode-Throughput Law and Its Cross-Hardware Validation
Madhulatha Mandarapu, Sandeep Kunkunuru
A columnar scan that decompresses, filters, and aggregates should be limited only by memory bandwidth (the roofline floor T >= BytesRead/beta), yet real kernels are often compute-b…