instances contain hidden columns that store this extra information that does not quite fit in the SQL object model.

OS X users can only have one JRE available through web browsers so OS X users can not have more than one JRE available through the web browser and will only only have JRE 8 available through the web browser after the upgrade.
Unless you have a support contract with Oracle or a license for Java SE Advanced products you will not be able to get security updates for JRE 7 from Oracle after April 2015 and it is not advisable to keep older versions of Java on your system.
Java Update is a feature that keeps your Windows computer up-to-date with the latest Java releases.
When you have auto update enabled, your system periodically checks for new versions of Java.
They also use an optimized in-memory DOM tree for processing, such as extracting XML documents or fragments.
wherever you use a user-defined type, including for table columns, views, trigger bodies, and type definitions.
Table 4-1 summarizes some advantages and disadvantages to consider when selecting your Oracle XML DB storage option.
functions use the built-in C parser and processor to parse XML data, validate it, and apply XPath expressions on it.
and these capabilities, SQL developers can leverage the power of the relational database while working in the context of XML.