by the client (might contain more than one statement)</entry>

</row>

<row>

<entry><literal><function>current_role</function></literal></entry>

<entry><type>name</type></entry>

<entry>equivalent to <function>current_user</function></entry>

</row>

<row>

<entry><literal><function>current_schema</function>[()]</literal></entry>

<entry><type>name</type></entry>

<note>

<para>

<function>current_catalog</function>, <function>current_schema</function>,

<function>current_user</function>, <function>session_user</function>,

<function>current_catalog</function>,

<function>current_role</function>,

<function>current_schema</function>,

<function>current_user</function>,

<function>session_user</function>,

and <function>user</function> have special syntactic status

in <acronym>SQL</acronym>: they must be called without trailing

parentheses. (In PostgreSQL, parentheses can optionally be used with

<primary>current_query</primary>

</indexterm>

<indexterm>

<primary>current_role</primary>

</indexterm>

<indexterm>

<primary>current_schema</primary>

</indexterm>

functions with the attribute <literal>SECURITY DEFINER</literal>.

In Unix parlance, the session user is the <quote>real user</quote> and

the current user is the <quote>effective user</quote>.

<function>current_role</function> and <function>user</function> are

synonyms for <function>current_user</function>. (The SQL standard draws

a distinction between <function>current_role</function>

and <function>current_user</function>, but <productname>PostgreSQL</>

does not, since it unifies users and roles into a single kind of entity.)

</para>

<para>