title: ORACLE DB user_constraints without tables
body: <p>I have an Oracle schema with no tables (I dropped them).  When I look at the <code>user_constraints</code> table, however</p>
  
  <pre><code>    SELECT * FROM user_constraints;
  </code></pre>
  
  <p>I see a number of rows. How is it possible to delete these constraints?</p>
  
  <pre><code>    DELETE FROM user_constraints WHERE owner='owner';
  </code></pre>
  
  <p>did not work, it gave me an "insufficient privileges" error.</p>
  
  <pre><code>    SELECT owner, constraint_name, constraint_type, table_name, r_owner, r_constraint_name  FROM user_constraints;
  
      OWNER                          CONSTRAINT_NAME                CONSTRAINT_TYPE TABLE_NAME                     R_OWNER                        R_CONSTRAINT_NAME            
      ORA_AI_1_9                     BIN$z2XwnFUHEHrgQ4sGOR4Qeg==$0 P               BIN$z2XwnFUJEHrgQ4sGOR4Qeg==$0                                                               
  
      ORA_AI_1_9                     BIN$z1NhC6g4oErgQ4sGOR6gSg==$0 P               BIN$z1NhC6g6oErgQ4sGOR6gSg==$0                                                               
  
      ORA_AI_1_9                     BIN$z1anK5OEEHrgQ4sGOR4Qeg==$0 P               BIN$z1anK5OGEHrgQ4sGOR4Qeg==$0                                                               
  
      ORA_AI_1_9                     BIN$z1NhC6hhoErgQ4sGOR6gSg==$0 P               BIN$z1NhC6hjoErgQ4sGOR6gSg==$0            
  </code></pre>