Extensions
Producing Alternative Means statistics with SQL
MySQL’s built-in AVG() computes the arithmetic mean — the sum divided by the count. That is the right default for many questions, but it is not always the right measure of central tendency.
Producing One-Sample Z-Test statistics with SQL
The one-sample Z-test determines whether a sample mean differs significantly from a known population mean when the population standard deviation is also known. It is the appropriate test when the population parameters are established — quality control benchmarks, national averages, long-run process measurements — and you want to evaluate whether a new sample is consistent with them.
Producing Skewness statistics with SQL
Skewness measures the asymmetry of a distribution. A perfectly symmetric distribution has a skewness of zero. A positive skew (right-skewed) means the tail extends to the right — a small number of high values pull the mean above the median.
Exploring the vsql-ai extension
The vsql-ai extension adds AI prompt capabilities and text embeddings directly in SQL queries, with support for Anthropic Claude , Google Gemini , OpenAI ChatGPT , or a local LLM such as Ollama .
Producing Chi-Squared statistics with SQL
The Chi-Squared test is one of the most widely used statistical tests for categorical data. It comes in two flavors: the goodness-of-fit test asks whether an observed frequency distribution matches an expected one, while the test of independence asks whether two categorical variables are associated with each other.
Producing Two Sample T-Test statistics with SQL
The two sample t-test for equal variance is a statistical test to determine if the means of two groups are different enough that the difference is likely caused by some underlying difference, rather than random chance.
Building your first VillageSQL Extension with AI skills
This is a technical walkthrough of the vsql-extension-builder recently released May 28 at Percona Live Bay Area 2026 and found at https://github.com/villagesql/villagesql-skills . Highlights Install VillageSQL pre-built binary first Install SDK with pre-built binary second Install the skill Run it with your AI tool The output can be found at https://github.