<!--
-$Header: /cvsroot/pgsql/doc/src/sgml/func.sgml,v 1.109 2002/08/08 14:29:07 tgl Exp $
+$Header: /cvsroot/pgsql/doc/src/sgml/func.sgml,v 1.110 2002/08/09 16:45:13 tgl Exp $
PostgreSQL documentation
-->
<literal>false</literal> instead. It is the equivalent to the SQL
<command>SET</command> command. For example:
<programlisting>
-SHOW show_query_stats;
- show_query_stats
-------------------
- on
-(1 row)
-
select set_config('show_query_stats','off','f');
set_config
------------
off
(1 row)
-
-SHOW show_query_stats;
- show_query_stats
-------------------
- off
-(1 row)
-
-select set_config('show_query_stats','on','t');
- set_config
-------------
- on
-(1 row)
-
-SHOW show_query_stats;
- show_query_stats
-------------------
- off
-(1 row)
-
-BEGIN;
-BEGIN
-select set_config('show_query_stats','on','t');
- set_config
-------------
- on
-(1 row)
-
-SHOW show_query_stats;
- show_query_stats
-------------------
- on
-(1 row)
-
-COMMIT;
-COMMIT
-SHOW show_query_stats;
- show_query_stats
-------------------
- off
-(1 row)
</programlisting>
</para>
<entry><type>boolean</type></entry>
<entry>does current user have access to table</entry>
</row>
+ <row>
+ <entry><function>has_database_privilege</function>(<parameter>user</parameter>,
+ <parameter>database</parameter>,
+ <parameter>access</parameter>)
+ </entry>
+ <entry><type>boolean</type></entry>
+ <entry>does user have access to database</entry>
+ </row>
+ <row>
+ <entry><function>has_database_privilege</function>(<parameter>database</parameter>,
+ <parameter>access</parameter>)
+ </entry>
+ <entry><type>boolean</type></entry>
+ <entry>does current user have access to database</entry>
+ </row>
+ <row>
+ <entry><function>has_function_privilege</function>(<parameter>user</parameter>,
+ <parameter>function</parameter>,
+ <parameter>access</parameter>)
+ </entry>
+ <entry><type>boolean</type></entry>
+ <entry>does user have access to function</entry>
+ </row>
+ <row>
+ <entry><function>has_function_privilege</function>(<parameter>function</parameter>,
+ <parameter>access</parameter>)
+ </entry>
+ <entry><type>boolean</type></entry>
+ <entry>does current user have access to function</entry>
+ </row>
+ <row>
+ <entry><function>has_language_privilege</function>(<parameter>user</parameter>,
+ <parameter>language</parameter>,
+ <parameter>access</parameter>)
+ </entry>
+ <entry><type>boolean</type></entry>
+ <entry>does user have access to language</entry>
+ </row>
+ <row>
+ <entry><function>has_language_privilege</function>(<parameter>language</parameter>,
+ <parameter>access</parameter>)
+ </entry>
+ <entry><type>boolean</type></entry>
+ <entry>does current user have access to language</entry>
+ </row>
+ <row>
+ <entry><function>has_schema_privilege</function>(<parameter>user</parameter>,
+ <parameter>schema</parameter>,
+ <parameter>access</parameter>)
+ </entry>
+ <entry><type>boolean</type></entry>
+ <entry>does user have access to schema</entry>
+ </row>
+ <row>
+ <entry><function>has_schema_privilege</function>(<parameter>schema</parameter>,
+ <parameter>access</parameter>)
+ </entry>
+ <entry><type>boolean</type></entry>
+ <entry>does current user have access to schema</entry>
+ </row>
</tbody>
</tgroup>
</table>
<indexterm zone="functions-misc">
<primary>has_table_privilege</primary>
</indexterm>
+ <indexterm zone="functions-misc">
+ <primary>has_database_privilege</primary>
+ </indexterm>
+ <indexterm zone="functions-misc">
+ <primary>has_function_privilege</primary>
+ </indexterm>
+ <indexterm zone="functions-misc">
+ <primary>has_language_privilege</primary>
+ </indexterm>
+ <indexterm zone="functions-misc">
+ <primary>has_schema_privilege</primary>
+ </indexterm>
<para>
- <function>has_table_privilege</function> determines whether a user
+ <function>has_table_privilege</function> checks whether a user
can access a table in a particular way. The user can be
specified by name or by ID
(<classname>pg_user</classname>.<structfield>usesysid</structfield>), or if the argument is
</programlisting>
</para>
+ <para>
+ <function>has_database_privilege</function> checks whether a user
+ can access a database in a particular way. The possibilities for its
+ arguments are analogous to <function>has_table_privilege</function>.
+ The desired access type must evaluate to
+ <literal>CREATE</literal>,
+ <literal>TEMPORARY</literal>, or
+ <literal>TEMP</literal> (which is equivalent to
+ <literal>TEMPORARY</literal>).
+ </para>
+
+ <para>
+ <function>has_function_privilege</function> checks whether a user
+ can access a function in a particular way. The possibilities for its
+ arguments are analogous to <function>has_table_privilege</function>.
+ When specifying a function by a text string rather than by OID,
+ the allowed input is the same as for the <type>regprocedure</> datatype.
+ The desired access type must currently evaluate to
+ <literal>EXECUTE</literal>.
+ </para>
+
+ <para>
+ <function>has_language_privilege</function> checks whether a user
+ can access a procedural language in a particular way. The possibilities
+ for its arguments are analogous to <function>has_table_privilege</function>.
+ The desired access type must currently evaluate to
+ <literal>USAGE</literal>.
+ </para>
+
+ <para>
+ <function>has_schema_privilege</function> checks whether a user
+ can access a schema in a particular way. The possibilities for its
+ arguments are analogous to <function>has_table_privilege</function>.
+ The desired access type must evaluate to
+ <literal>CREATE</literal> or
+ <literal>USAGE</literal>.
+ </para>
+
+ <table>
+ <title>Schema Visibility Inquiry Functions</title>
+ <tgroup cols="3">
+ <thead>
+ <row><entry>Name</entry> <entry>Return Type</entry> <entry>Description</entry></row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry><function>pg_table_is_visible</function>(<parameter>tableOID</parameter>)
+ </entry>
+ <entry><type>boolean</type></entry>
+ <entry>is table visible in search path</entry>
+ </row>
+ <row>
+ <entry><function>pg_type_is_visible</function>(<parameter>typeOID</parameter>)
+ </entry>
+ <entry><type>boolean</type></entry>
+ <entry>is type visible in search path</entry>
+ </row>
+ <row>
+ <entry><function>pg_function_is_visible</function>(<parameter>functionOID</parameter>)
+ </entry>
+ <entry><type>boolean</type></entry>
+ <entry>is function visible in search path</entry>
+ </row>
+ <row>
+ <entry><function>pg_operator_is_visible</function>(<parameter>operatorOID</parameter>)
+ </entry>
+ <entry><type>boolean</type></entry>
+ <entry>is operator visible in search path</entry>
+ </row>
+ <row>
+ <entry><function>pg_opclass_is_visible</function>(<parameter>opclassOID</parameter>)
+ </entry>
+ <entry><type>boolean</type></entry>
+ <entry>is operator class visible in search path</entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+
+ <indexterm zone="functions-misc">
+ <primary>pg_table_is_visible</primary>
+ </indexterm>
+ <indexterm zone="functions-misc">
+ <primary>pg_type_is_visible</primary>
+ </indexterm>
+ <indexterm zone="functions-misc">
+ <primary>pg_function_is_visible</primary>
+ </indexterm>
+ <indexterm zone="functions-misc">
+ <primary>pg_operator_is_visible</primary>
+ </indexterm>
+ <indexterm zone="functions-misc">
+ <primary>pg_opclass_is_visible</primary>
+ </indexterm>
+
+ <para>
+ <function>pg_table_is_visible</function> checks whether a table
+ (or view, or any other kind of <structname>pg_class</> entry) is
+ <firstterm>visible</> in the current schema search path. A table
+ is said to be visible if its containing schema is in the search path
+ and no table of the same name appears earlier in the search path.
+ This is equivalent to the statement that the table can be referenced
+ by name without explicit schema qualification.
+ For example, to list the names of all visible tables:
+<programlisting>
+SELECT relname FROM pg_class WHERE pg_table_is_visible(oid);
+</programlisting>
+ </para>
+
+ <para>
+ <function>pg_type_is_visible</function>,
+ <function>pg_function_is_visible</function>,
+ <function>pg_operator_is_visible</function>, and
+ <function>pg_opclass_is_visible</function> perform the same sort of
+ visibility check for types, functions, operators, and operator classes,
+ respectively. For functions and operators, an object in the search path
+ is visible if there is no object of the same name <emphasis>and argument
+ datatype(s)</> earlier in the path. For operator classes,
+ both name and associated index access method are considered.
+ </para>
+
+ <para>
+ All these functions require object OIDs to identify the object to be
+ checked. If you want to test an object by name, it is convenient to use
+ the OID alias types (<type>regclass</>, <type>regtype</>,
+ <type>regprocedure</>, or <type>regoperator</>), for example
+<programlisting>
+SELECT pg_type_is_visible('myschema.widget'::regtype);
+</programlisting>
+ Note that it would not make much sense to test an unqualified name in
+ this way --- if the name can be recognized at all, it must be visible.
+ </para>
+
<table>
<title>Catalog Information Functions</title>
<tgroup cols="3">
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