The article by Robin Moffatt explores how to leverage the Elastic Stack, comprising Elasticsearch, Logstash, and Kibana, to visualize Oracle database performance data, specifically focusing on Active Session History (ASH) data. The Elastic Stack offers an open-source, flexible solution for diagnosing Oracle database performance issues by allowing users to stream, store, and analyze data in a customizable way. By using Logstash's JDBC input plugin to pull data from Oracle's V$ACTIVE_SESSION_HISTORY table, the data is streamed into Elasticsearch for storage and analysis with Kibana. The article details the setup process, which includes configuring Logstash to poll Oracle data continually and sending it to Elasticsearch while resolving any data type issues that arise. Kibana is then used to create visualizations and dashboards, enabling interactive analysis of Oracle performance data. The Elastic Stack's ability to integrate seamlessly and scale horizontally makes it a powerful tool for monitoring and diagnosing database performance, as demonstrated through various examples and visualizations.