A view is a tailored presentation of the data contained in one or more tables (or other views), and takes the output of a query and treats it as a table.You can think of a view as a "stored query" or a "virtual table." You can use views in most places where a table can be used.The owner of the schema containing the view must have the privileges necessary to either select, insert, update, or delete rows from all the tables or views on which the view is based.The owner must be granted these privileges directly, rather than through a role.Oracle recommends that you use partitioned tables rather than partition views in most operational environments. You can use this clause to change the definition of an existing view without dropping, re-creating, and regranting object privileges previously granted on it.if you want to create the view regardless of whether the view's base tables or the referenced object types exist or the owner of the schema containing the view has privileges on them. If you omit Specify names for the expressions selected by the view's query.For information changing conditions and their impact on views, see "Managing Object Dependencies".
You could have this in a security policy if you want to restrict access to tables to only Discoverer.To replicate updates to LOB columns in transactional publications, consider one of the following strategies when writing the application: For both snapshot and transactional replication, columns contained in unique indexes and constraints (including primary key constraints) must adhere to certain restrictions.If they do not adhere to these restrictions, the constraint or index is not replicated.Large object (LOB) data is not stored in the article log table; updates to LOB data are always retrieved directly from the published table.Updates are replicated in transactional publications only if the operation affecting the LOB fires the replication trigger on the replicated table.