The USETABLENAME environment variable can prevent
users from using a synonym to specify the table in ALTER TABLE
or DROP TABLE statements. Unlike most environment variables, USETABLENAME is
not required to be set to a value. It takes effect if you set it to
any value, or to no value.
By default, ALTER TABLE or DROP TABLE statements
accept a valid synonym for the name of the table to be altered
or dropped. (In contrast, RENAME TABLE issues an error if you specify
a synonym, as do the ALTER SEQUENCE, DROP SEQUENCE, and RENAME SEQUENCE
statements, if you attempt to substitute a synonym for the sequence name
in those statements.)
If you set USETABLENAME, an error
results if a synonym is in ALTER TABLE or DROP TABLE statements. Setting USETABLENAME has
no effect on the DROP VIEW statement, which accepts a valid synonym
for the view.