Use the CREATE SYNONYM statement to provide an alternate name
for a table or a view that is present in the same schema or another schema.
You can also create synonyms for other synonyms, resulting in nested synonyms.
A synonym can be used instead of the original qualified table or view name
in SELECT, INSERT, UPDATE, DELETE or LOCK TABLE statements. You can create
a synonym for a table or a view that doesn't exist, but the target table or
view must be present before the synonym can be used.
Synonyms share
the same namespace as tables or views. You cannot create a synonym with the
same name as a table that already exists in the same schema. Similarly, you
cannot create a table or view with a name that matches a synonym already present.
A
synonym can be defined for a table/view that does not exist when you create
the synonym. If the table or view doesn't exist, you will receive a warning
message (SQLSTATE 01522). The referenced object must be present when you
use a synonym in a DML statement.
You can create a nested synonym (a
synonym for another synonym), but any attempt to create a synonym that results
in a circular reference will return an error message (SQLSTATE 42916).
Synonyms cannot be defined in system schemas. All schemas starting with 'SYS' are considered system schemas and are reserved by Derby.
A synonym cannot
be defined on a temporary table. Attempting to define a synonym on a temporary
table will return an error message (SQLSTATE XCL51).
