automatically-generated constraint names avoid duplicates in the

same schema, but users can specify such duplicate names.

</para>

<para>

This problem can appear when querying information schema views like

<literal>referential_constraints</>, <literal>check_constraints</>,

<literal>domain_constraints</>, and

<literal>check_constraint_routine_usage</>. Some other views have

similar issues but contain the table name to help distinguish

duplicate rows, e.g. <literal>table_constraints</>,

<literal>constraint_table_usage</>, <literal>constraint_column_usage</>.

</para>

</note>