Answer
The GDB_Items table maintains information about all the items stored in the geodatabase and the DEFINITION column of this table stores information about each item.
In ArcSDE for SQL Server, PostgreSQL or DB2 geodatabases, the DEFINITION column uses a native XML data type for each respective DBMS. Therefore, XPath statements can be used within SQL queries to retrieve information from this column. Please see the Related Information section for sample queries.
In Oracle geodatabases, the DEFINITION column is an ArcSDE XML type rather than the native Oracle XML type which stores the information as BLOBs. To enable reading these values, the SDE schema in Oracle contains a view for the GDB_Items table named GDB_Items_vw. This view replaces the XML columns of the actual table with CLOB columns that can be read as text. The text string must be extracted from the CLOB column and converted to XML in order to use XPath statements to query the data from the DEFINITION column.