I need to collect information about test cases and test execution results directly from JIRA DB (Oracle 11g) with Zephyr plugin but I cannot find where exactly that information is stored by the plugin. Can someone share typical DB schema for Zephyr plugin? For now I only could find that testcases are the same as jira's issues and stored together in jiraissue table and information about executions are somewhere like 'AO_%' tables.
You can list out the AO_* tables-to-plugins relations inside JIRA. It's under Administration >> System >> Advanced/Plugin Data Storage. (eg: https://yourjiraserver/plugins/servlet/active-objects/tables/list)
Here, you should find "Zephyr for JIRA" in the first column, and the second column will tell all the tables you have regarding this plugin.