Oracle Open World Presentations

<p>
  At <a href="http://orancle.com/openworld">Oracle Open World 2011</a> there has been a large number of MySQL presentations. You can download the slides of my two presentations at <a href="http://effectivemysql.com/downloads/ExplainingTheMySQLEXPLAIN-OOW-2011.pdf">Explaining the MySQL Explain</a> and <a href="http://effectivemysql.com/downloads/ImprovingPerformanceWithBetterIndexes-OOW-2011.pdf">Improving Performance with Better Indexes</a>.
</p>

<p>
  You can find additional supporting information for these presentations in the <a href="http://effectivemysql.com/book/optimizing-sql-statements/">Effective MySQL: Optimizing SQL Statements</a> book.
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Tagged with: Databases MySQL MySQL Events

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.