<note>
<para>
- The SQL standard requires constraint names to be unique within a
- schema; <productname>PostgreSQL</productname>, however, does not
- enforce this restriction. If duplicate-named constraints are
- stored in the same <productname>PostgreSQL</productname> schema,
- a standard-compliant query that expects to return one matching
- constraint row might return several, one row for each matching
- constraint stored in the specified schema.
+ When querying the database for constraint information, it is possible
+ for a standard-compliant query that expects to return one row to
+ return several. This is because the SQL standard requires constraint
+ names to be unique within a schema, but
+ <productname>PostgreSQL</productname> does not enforce this
+ restriction. <productname>PostgreSQL</productname>
+ automatically-generated constraint names avoid duplicates in the
+ same schema, but users can specify such duplicate names.
</para>
</note>