<primary>pg_shadow</primary>
  </indexterm>

  <para>
   The view <structname>pg_shadow</structname> exists for backwards
   compatibility: it emulates a catalog that existed in
   <productname>PostgreSQL</productname> before version 8.1.
   It shows properties of all roles that are marked as
   <structfield>rolcanlogin</structfield> in
   <link linkend="catalog-pg-authid"><structname>pg_authid</structname></link>.
  </para>

  <para>
   The name stems from the fact that this table
   should not be readable by the public since it contains passwords.
   <link linkend="view-pg-user"><structname>pg_user</structname></link>
   is a publicly readable view on
   <structname>pg_shadow</structname> that blanks out the password field.
  </para>

  <table>
   <title><structname>pg_shadow</structname> Columns</title>
   <tgroup cols="1">
    <thead>
     <row>
      <entry role="catalog_table_entry"><para role="column_definition">
       Column Type
      </para>
      <para>
       Description
      </para></entry>
     </row>
    </thead>

    <tbody>
     <row>
      <entry role="catalog_table_entry"><para role="column_definition">
       <structfield>usename</structfield> <type>name</type>
       (references <link linkend="catalog-pg-authid"><structname>pg_authid</structname></link>.<structfield>rolname</structfield>)
      </para>
      <para>
       User name
      </para></entry>
     </row>

     <row>
      <entry role="catalog_table_entry"><para role="column_definition">
       <structfield>usesysid</structfield> <type>oid</type>
       (references <link linkend="catalog-pg-authid"><structname>pg_authid</structname></link>.<structfield>oid</structfield>)
      </para>
      <para>
       ID of this user
      </para></entry>
     </row>

     <row>
      <entry role="catalog_table_entry"><para role="column_definition">
       <structfield>usecreatedb</structfield> <type>bool</type>
      </para>
      <para>
       User can create databases
      </para></entry>
     </row>

     <row>
      <entry role="catalog_table_entry"><para role="column_definition">
       <structfield>usesuper</structfield> <type>bool</type>
      </para>
      <para>
       User is a superuser
      </para></entry>
     </row>

     <row>
      <entry role="catalog_table_entry"><para role="column_definition">
       <structfield>userepl</structfield> <type>bool</type>
      </para>
      <para>
       User can initiate streaming replication and put the system in and
       out of backup mode.
      </para></entry>
     </row>

     <row>
      <entry role="catalog_table_entry"><para role="column_definition">
       <structfield>usebypassrls</structfield> <type>bool</type>
      </para>
      <para>
       User bypasses every row-level security policy, see
       <xref linkend="ddl-rowsecurity"/> for more information.
      </para></entry>
     </row>

     <row>
      <entry role="catalog_table_entry"><para role="column_definition">
       <structfield>passwd</structfield> <type>text</type>
      </para>
      <para>
       Encrypted password; null if none.  See
       <link linkend="catalog-pg-authid"><structname>pg_authid</structname></link>
       for details of how encrypted passwords are stored.
      </para></entry>
     </row>

     <row>
      <entry role="catalog_table_entry"><para role="column_definition">
       <structfield>valuntil</structfield> <type>timestamptz</type>
      </para>
      <para>
       Password expiry time (only used for password authentication)
      </para></entry>
     </row>

     <row>
      <entry role="catalog_table_entry"><para role="column_definition">
       <structfield>useconfig</structfield> <type>text[]</type>
      </para>
      <para>
       Session defaults for run-time configuration variables
      </para></entry>
     </row>
    </tbody>
   </tgroup>
  </table>

 </sect1>

 <sect1 id="view-pg-shmem-allocations">
  <title><structname>pg_shmem_allocations</structname></title>

  <indexterm zone="view-pg-shmem-allocations">