@ -1396,6 +1396,10 @@ ALTER TABLE products RENAME TO items;
<primary>REVOKE</primary>
</indexterm>
<indexterm zone="ddl-priv">
<primary>ACL</primary>
</indexterm>
<para>
When an object is created, it is assigned an owner. The
owner is normally the role that executed the creation statement.
@ -1413,11 +1417,9 @@ ALTER TABLE products RENAME TO items;
<literal>EXECUTE</literal>, and <literal>USAGE</literal>.
The privileges applicable to a particular
object vary depending on the object's type (table, function, etc).
For complete information on the different types of privileges
supported by <productname>PostgreSQL</productname>, refer to the
<xref linkend="sql-grant"/> reference
page. The following sections and chapters will also show you how
those privileges are used.
More detail about the meanings of these privileges appears below.
The following sections and chapters will also show you how
these privileges are used.
</para>
<para>
@ -1427,15 +1429,17 @@ ALTER TABLE products RENAME TO items;
<para>
An object can be assigned to a new owner with an <command>ALTER</command>
command of the appropriate kind for the object, e.g. <xref
linkend="sql-altertable"/>. Superusers can always do
this; ordinary roles can only do it if they are both the current owner
of the object (or a member of the owning role) and a member of the new
owning role.
command of the appropriate kind for the object, for example
<programlisting>
ALTER TABLE <replaceable>table_name</replaceable> OWNER TO <replaceable>new_owner</replaceable>;
</programlisting>
Superusers can always do this; ordinary roles can only do it if they are
both the current owner of the object (or a member of the owning role) and
a member of the new owning role.
</para>
<para>
To assign privileges, the <command>GRANT</command > command is
To assign privileges, the <xref linkend="sql-grant"/ > command is
used. For example, if <literal>joe</literal> is an existing role, and
<literal>accounts</literal> is an existing table, the privilege to
update the table can be granted with:
@ -1456,7 +1460,7 @@ GRANT UPDATE ON accounts TO joe;
<para>
To revoke a privilege, use the fittingly named
<command>REVOKE</command > command:
<xref linkend="sql-revoke"/ > command:
<programlisting>
REVOKE ALL ON accounts FROM PUBLIC;
</programlisting>
@ -1478,6 +1482,507 @@ REVOKE ALL ON accounts FROM PUBLIC;
privilege. For details see the <xref linkend="sql-grant"/> and
<xref linkend="sql-revoke"/> reference pages.
</para>
<para>
The available privileges are:
<variablelist>
<varlistentry>
<term><literal>SELECT</literal></term>
<listitem>
<para>
Allows <xref linkend="sql-select"/> from
any column, or specific column(s), of a table, view, materialized
view, or other table-like object.
Also allows use of <xref linkend="sql-copy"/> TO.
This privilege is also needed to reference existing column values in
<xref linkend="sql-update"/> or <xref linkend="sql-delete"/>.
For sequences, this privilege also allows use of the
<function>currval</function> function.
For large objects, this privilege allows the object to be read.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><literal>INSERT</literal></term>
<listitem>
<para>
Allows <xref linkend="sql-insert"/> of a new row into a table, view,
etc. Can be granted on specific column(s), in which case
only those columns may be assigned to in the <command>INSERT</command>
command (other columns will therefore receive default values).
Also allows use of <xref linkend="sql-copy"/> FROM.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><literal>UPDATE</literal></term>
<listitem>
<para>
Allows <xref linkend="sql-update"/> of any
column, or specific column(s), of a table, view, etc.
(In practice, any nontrivial <command>UPDATE</command> command will
require <literal>SELECT</literal> privilege as well, since it must
reference table columns to determine which rows to update, and/or to
compute new values for columns.)
<literal>SELECT ... FOR UPDATE</literal>
and <literal>SELECT ... FOR SHARE</literal>
also require this privilege on at least one column, in addition to the
<literal>SELECT</literal> privilege. For sequences, this
privilege allows use of the <function>nextval</function> and
<function>setval</function> functions.
For large objects, this privilege allows writing or truncating the
object.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><literal>DELETE</literal></term>
<listitem>
<para>
Allows <xref linkend="sql-delete"/> of a row from a table, view, etc.
(In practice, any nontrivial <command>DELETE</command> command will
require <literal>SELECT</literal> privilege as well, since it must
reference table columns to determine which rows to delete.)
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><literal>TRUNCATE</literal></term>
<listitem>
<para>
Allows <xref linkend="sql-truncate"/> on a table, view, etc.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><literal>REFERENCES</literal></term>
<listitem>
<para>
Allows creation of a foreign key constraint referencing a
table, or specific column(s) of a table.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><literal>TRIGGER</literal></term>
<listitem>
<para>
Allows creation of a trigger on a table, view, etc.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><literal>CREATE</literal></term>
<listitem>
<para>
For databases, allows new schemas and publications to be created within
the database.
</para>
<para>
For schemas, allows new objects to be created within the schema.
To rename an existing object, you must own the
object <emphasis>and</emphasis> have this privilege for the containing
schema.
</para>
<para>
For tablespaces, allows tables, indexes, and temporary files to be
created within the tablespace, and allows databases to be created that
have the tablespace as their default tablespace. (Note that revoking
this privilege will not alter the placement of existing objects.)
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><literal>CONNECT</literal></term>
<listitem>
<para>
Allows the grantee to connect to the database. This
privilege is checked at connection startup (in addition to checking
any restrictions imposed by <filename>pg_hba.conf</filename>).
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><literal>TEMPORARY</literal></term>
<listitem>
<para>
Allows temporary tables to be created while using the database.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><literal>EXECUTE</literal></term>
<listitem>
<para>
Allows calling a function or procedure, including use of
any operators that are implemented on top of the function. This is the
only type of privilege that is applicable to functions and procedures.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><literal>USAGE</literal></term>
<listitem>
<para>
For procedural languages, allows use of the language for
the creation of functions in that language. This is the only type
of privilege that is applicable to procedural languages.
</para>
<para>
For schemas, allows access to objects contained in the
schema (assuming that the objects' own privilege requirements are
also met). Essentially this allows the grantee to <quote>look up</quote>
objects within the schema. Without this permission, it is still
possible to see the object names, e.g. by querying system catalogs.
Also, after revoking this permission, existing sessions might have
statements that have previously performed this lookup, so this is not
a completely secure way to prevent object access.
</para>
<para>
For sequences, allows use of the
<function>currval</function> and <function>nextval</function> functions.
</para>
<para>
For types and domains, allows use of the type or domain in the
creation of tables, functions, and other schema objects. (Note that
this privilege does not control all <quote>usage</quote> of the
type, such as values of the type appearing in queries. It only
prevents objects from being created that depend on the type. The
main purpose of this privilege is controlling which users can create
dependencies on a type, which could prevent the owner from changing
the type later.)
</para>
<para>
For foreign-data wrappers, allows creation of new servers using the
foreign-data wrapper.
</para>
<para>
For foreign servers, allows creation of foreign tables using the
server. Grantees may also create, alter, or drop their own user
mappings associated with that server.
</para>
</listitem>
</varlistentry>
</variablelist>
The privileges required by other commands are listed on the
reference page of the respective command.
</para>
<para>
PostgreSQL grants privileges on some types of objects to
<literal>PUBLIC</literal> by default when the objects are created.
No privileges are granted to <literal>PUBLIC</literal> by default on
tables,
table columns,
sequences,
foreign data wrappers,
foreign servers,
large objects,
schemas,
or tablespaces.
For other types of objects, the default privileges
granted to <literal>PUBLIC</literal> are as follows:
<literal>CONNECT</literal> and <literal>TEMPORARY</literal> (create
temporary tables) privileges for databases;
<literal>EXECUTE</literal> privilege for functions and procedures; and
<literal>USAGE</literal> privilege for languages and data types
(including domains).
The object owner can, of course, <command>REVOKE</command>
both default and expressly granted privileges. (For maximum
security, issue the <command>REVOKE</command> in the same transaction that
creates the object; then there is no window in which another user
can use the object.)
Also, these default privilege settings can be overridden using the
<xref linkend="sql-alterdefaultprivileges"/> command.
</para>
<para>
<xref linkend="privilege-abbrevs-table"/> shows the one-letter
abbreviations that are used for these privilege types in
<firstterm>ACL</firstterm> (Access Control List) values.
You will see these letters in the output of the <xref linkend="app-psql"/>
commands listed below, or when looking at ACL columns of system catalogs.
</para>
<table id="privilege-abbrevs-table">
<title>ACL Privilege Abbreviations</title>
<tgroup cols="3">
<thead>
<row>
<entry>Privilege</entry>
<entry>Abbreviation</entry>
<entry>Applicable Object Types</entry>
</row>
</thead>
<tbody>
<row>
<entry><literal>SELECT</literal></entry>
<entry><literal>r</literal> (<quote>read</quote>)</entry>
<entry>
<literal>LARGE OBJECT</literal>,
<literal>SEQUENCE</literal>,
<literal>TABLE</literal> (and table-like objects),
table column
</entry>
</row>
<row>
<entry><literal>INSERT</literal></entry>
<entry><literal>a</literal> (<quote>append</quote>)</entry>
<entry><literal>TABLE</literal>, table column</entry>
</row>
<row>
<entry><literal>UPDATE</literal></entry>
<entry><literal>w</literal> (<quote>write</quote>)</entry>
<entry>
<literal>LARGE OBJECT</literal>,
<literal>SEQUENCE</literal>,
<literal>TABLE</literal>,
table column
</entry>
</row>
<row>
<entry><literal>DELETE</literal></entry>
<entry><literal>d</literal></entry>
<entry><literal>TABLE</literal></entry>
</row>
<row>
<entry><literal>TRUNCATE</literal></entry>
<entry><literal>D</literal></entry>
<entry><literal>TABLE</literal></entry>
</row>
<row>
<entry><literal>REFERENCES</literal></entry>
<entry><literal>x</literal></entry>
<entry><literal>TABLE</literal>, table column</entry>
</row>
<row>
<entry><literal>TRIGGER</literal></entry>
<entry><literal>t</literal></entry>
<entry><literal>TABLE</literal></entry>
</row>
<row>
<entry><literal>CREATE</literal></entry>
<entry><literal>C</literal></entry>
<entry>
<literal>DATABASE</literal>,
<literal>SCHEMA</literal>,
<literal>TABLESPACE</literal>
</entry>
</row>
<row>
<entry><literal>CONNECT</literal></entry>
<entry><literal>c</literal></entry>
<entry><literal>DATABASE</literal></entry>
</row>
<row>
<entry><literal>TEMPORARY</literal></entry>
<entry><literal>T</literal></entry>
<entry><literal>DATABASE</literal></entry>
</row>
<row>
<entry><literal>EXECUTE</literal></entry>
<entry><literal>X</literal></entry>
<entry><literal>FUNCTION</literal>, <literal>PROCEDURE</literal></entry>
</row>
<row>
<entry><literal>USAGE</literal></entry>
<entry><literal>U</literal></entry>
<entry>
<literal>DOMAIN</literal>,
<literal>FOREIGN DATA WRAPPER</literal>,
<literal>FOREIGN SERVER</literal>,
<literal>LANGUAGE</literal>,
<literal>SCHEMA</literal>,
<literal>SEQUENCE</literal>,
<literal>TYPE</literal>
</entry>
</row>
</tbody>
</tgroup>
</table>
<para>
<xref linkend="privileges-summary-table"/> summarizes the privileges
available for each type of SQL object, using the abbreviations shown
above.
It also shows the <application>psql</application> command
that can be used to examine privilege settings for each object type.
</para>
<table id="privileges-summary-table">
<title>Summary of Access Privileges</title>
<tgroup cols="4">
<thead>
<row>
<entry>Object Type</entry>
<entry>All Privileges</entry>
<entry>Default <literal>PUBLIC</literal> Privileges</entry>
<entry><application>psql</application> Command</entry>
</row>
</thead>
<tbody>
<row>
<entry><literal>DATABASE</literal></entry>
<entry><literal>CTc</literal></entry>
<entry><literal>Tc</literal></entry>
<entry><literal>\l</literal></entry>
</row>
<row>
<entry><literal>DOMAIN</literal></entry>
<entry><literal>U</literal></entry>
<entry><literal>U</literal></entry>
<entry><literal>\dD+</literal></entry>
</row>
<row>
<entry><literal>FUNCTION</literal> or <literal>PROCEDURE</literal></entry>
<entry><literal>X</literal></entry>
<entry><literal>X</literal></entry>
<entry><literal>\df+</literal></entry>
</row>
<row>
<entry><literal>FOREIGN DATA WRAPPER</literal></entry>
<entry><literal>U</literal></entry>
<entry>none</entry>
<entry><literal>\dew+</literal></entry>
</row>
<row>
<entry><literal>FOREIGN SERVER</literal></entry>
<entry><literal>U</literal></entry>
<entry>none</entry>
<entry><literal>\des+</literal></entry>
</row>
<row>
<entry><literal>LANGUAGE</literal></entry>
<entry><literal>U</literal></entry>
<entry><literal>U</literal></entry>
<entry><literal>\dL+</literal></entry>
</row>
<row>
<entry><literal>LARGE OBJECT</literal></entry>
<entry><literal>rw</literal></entry>
<entry>none</entry>
<entry></entry>
</row>
<row>
<entry><literal>SCHEMA</literal></entry>
<entry><literal>UC</literal></entry>
<entry>none</entry>
<entry><literal>\dn+</literal></entry>
</row>
<row>
<entry><literal>SEQUENCE</literal></entry>
<entry><literal>rwU</literal></entry>
<entry>none</entry>
<entry><literal>\dp</literal></entry>
</row>
<row>
<entry><literal>TABLE</literal> (and table-like objects)</entry>
<entry><literal>arwdDxt</literal></entry>
<entry>none</entry>
<entry><literal>\dp</literal></entry>
</row>
<row>
<entry>Table column</entry>
<entry><literal>arwx</literal></entry>
<entry>none</entry>
<entry><literal>\dp</literal></entry>
</row>
<row>
<entry><literal>TABLESPACE</literal></entry>
<entry><literal>C</literal></entry>
<entry>none</entry>
<entry><literal>\db+</literal></entry>
</row>
<row>
<entry><literal>TYPE</literal></entry>
<entry><literal>U</literal></entry>
<entry><literal>U</literal></entry>
<entry><literal>\dT+</literal></entry>
</row>
</tbody>
</tgroup>
</table>
<para>
<indexterm>
<primary><type>aclitem</type></primary>
</indexterm>
The privileges that have been granted for a particular object are
displayed as a list of <type>aclitem</type> entries, where each
<type>aclitem</type> describes the permissions of one grantee that
have been granted by a particular grantor. For example,
<literal>calvin=r*w/hobbes</literal> specifies that the role
<literal>calvin</literal> has the privilege
<literal>SELECT</literal> (<literal>r</literal>) with grant option
(<literal>*</literal>) as well as the non-grantable
privilege <literal>UPDATE</literal> (<literal>w</literal>), both granted
by the role <literal>hobbes</literal>. If <literal>calvin</literal>
also has some privileges on the same object granted by a different
grantor, those would appear as a separate <type>aclitem</type> entry.
An empty grantee field in an <type>aclitem</type> stands
for <literal>PUBLIC</literal>.
</para>
<para>
As an example, suppose that user <literal>miriam</literal> creates
table <literal>mytable</literal> and does:
<programlisting>
GRANT SELECT ON mytable TO PUBLIC;
GRANT SELECT, UPDATE, INSERT ON mytable TO admin;
GRANT SELECT (col1), UPDATE (col1) ON mytable TO miriam_rw;
</programlisting>
Then <application>psql</application>'s <literal>\dp</literal> command
would show:
<programlisting>
=> \dp mytable
Access privileges
Schema | Name | Type | Access privileges | Column privileges | Policies
--------+---------+-------+-----------------------+-----------------------+----------
public | mytable | table | miriam=arwdDxt/miriam+| col1: +|
| | | =r/miriam +| miriam_rw=rw/miriam |
| | | admin=arw/miriam | |
(1 row)
</programlisting>
</para>
<para>
If the <quote>Access privileges</quote> column is empty for a given
object, it means the object has default privileges (that is, its
privileges entry in the relevant system catalog is null). Default
privileges always include all privileges for the owner, and can include
some privileges for <literal>PUBLIC</literal> depending on the object
type, as explained above. The first <command>GRANT</command>
or <command>REVOKE</command> on an object will instantiate the default
privileges (producing, for
example, <literal>miriam=arwdDxt/miriam</literal>) and then modify them
per the specified request. Similarly, entries are shown in <quote>Column
privileges</quote> only for columns with nondefault privileges.
(Note: for this purpose, <quote>default privileges</quote> always means
the built-in default privileges for the object's type. An object whose
privileges have been affected by an <command>ALTER DEFAULT
PRIVILEGES</command> command will always be shown with an explicit
privilege entry that includes the effects of
the <command>ALTER</command>.)
</para>
<para>
Notice that the owner's implicit grant options are not marked in the
access privileges display. A <literal>*</literal> will appear only when
grant options have been explicitly granted to someone.
</para>
</sect1>
<sect1 id="ddl-rowsecurity">
Tom Lane
7 years ago