The system table /services/databases/system/ALL_COLUMNS can be queried. Before querying the systems table, the resource whose column attributes you wish to view should be published.
Example Let us say that I have an introspected an Oracle table '/users/composite/admin/DATASOURCES/ora_ds/JOE/EMPLOYEE', and I want to see the definitions of the columns in the table.
(1) Publish the table (e.g. as /services/databases/examples/EMPLOYEE)
(2) Run a query on ALL_COLUMNS, and filter the results on TABLE_NAME as shown below:
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SELECT * from /services/databases/system/ALL_COLUMNS
where
DATASOURCE_NAME like '%examples%'
and
TABLE_NAME = 'employee'
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