Research11 min read
Why Sigmoid? The Mathematical Inevitability Behind Bayesian BM25
by Jaepil Jeong | February 23, 2026
Sigmoid is not a design choice — it is a mathematical theorem. We show why the sigmoid function is the unique valid transform for converting BM25 scores to probabilities, completing Robertson's Probability Ranking Principle after 50 years.
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Tech15 min read
Building a Probabilistic Search Engine: Bayesian BM25 and Hybrid Search
by Jaepil Jeong | February 1, 2026
Modern search systems struggle to combine lexical matching with semantic understanding. We explore how we built a probabilistic ranking framework in Cognica Database that transforms BM25 scores into calibrated probabilities, enabling principled fusion of text and vector search results.
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Insights5 min read
Supporting Business Decision-Making Through Single Database ERP: Practical Applications of AI
by Tim Yang | October 12, 2025
Cognica ERP eliminates the complexity of data integration, instantly providing answers not only to 'what' but also 'why' and 'what's next,' creating business competitiveness.
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Engineering14 min read
Why Did We Store Two-Dimensional Vectors for Vector Search?
by Cognica Team | July 17, 2024
Explains the limitations and characteristics of vector embeddings and covers the improvements made to store them.
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Insights5 min read
Why Did OpenAI Acquire Rockset?
by Tim Yang | July 11, 2024
On June 21, 2024, OpenAI announced the acquisition of database startup Rockset. According to OpenAI, the background of the Rockset acquisition is to improve search infrastructure to make AI more useful. Specifically, what advantages led OpenAI to acquire Rockset?
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Engineering13 min read
Searching Case Law Data with Natural Language
by Cognica Team | July 4, 2024
Explains how to build a natural language search service by applying vector search to a case law search demo using FTS.
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Engineering10 min read
Making Case Law Data Quickly Searchable
by Cognica Team | June 21, 2024
Explains the process of downloading case law data and building a case law search service in just one day using Cognica.
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Engineering20 min read
Applying Natural Language Search to Product Search
by Cognica Team | June 12, 2024
We explain the process of data collection and processing, search, and service development for product search using Cognica. Learn how to index when structured and unstructured data are mixed, and how to transform queries for search using LLM.
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Insights5 min read
An AI Database for RAG (Retrieval Augmented Generation)
by Tim Yang | December 11, 2023
You can easily create RAG (Retrieval Augmented Generation) with just one AI database without complex infrastructure setup.
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Case Studies9 min read
Case Study, Developing a Q&A System Using Vector DB and LLM
by Tim Yang | September 17, 2023
Methods to overcome the limitations of Large Language Models (LLMs) by utilizing Vector Databases (VectorDBs) are gaining attention. To provide accurate answers on specialized information such as law firm case precedents or company communication records—domain data that is not included in the training data—we can use a Vector Database that can convert, store, and search all kinds of data into vector embeddings, serving as a long-term memory storage for LLMs. To illustrate this, we examine a concrete case of how a vector database can complement an LLM through processes like data preprocessing, vectorization, storage, and search, using a Q&A system based on Wikipedia.
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