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diff --git a/doc/src/sgml/ref/alter_foreign_table.sgml b/doc/src/sgml/ref/alter_foreign_table.sgml new file mode 100644 index 0000000..5d373ae --- /dev/null +++ b/doc/src/sgml/ref/alter_foreign_table.sgml @@ -0,0 +1,556 @@ +<!-- +doc/src/sgml/rel/alter_foreign_table.sgml +PostgreSQL documentation +--> + +<refentry id="sql-alterforeigntable"> + <indexterm zone="sql-alterforeigntable"> + <primary>ALTER FOREIGN TABLE</primary> + </indexterm> + + <refmeta> + <refentrytitle>ALTER FOREIGN TABLE</refentrytitle> + <manvolnum>7</manvolnum> + <refmiscinfo>SQL - Language Statements</refmiscinfo> + </refmeta> + + <refnamediv> + <refname>ALTER FOREIGN TABLE</refname> + <refpurpose>change the definition of a foreign table</refpurpose> + </refnamediv> + + <refsynopsisdiv> +<synopsis> +ALTER FOREIGN TABLE [ IF EXISTS ] [ ONLY ] <replaceable class="parameter">name</replaceable> [ * ] + <replaceable class="parameter">action</replaceable> [, ... ] +ALTER FOREIGN TABLE [ IF EXISTS ] [ ONLY ] <replaceable class="parameter">name</replaceable> [ * ] + RENAME [ COLUMN ] <replaceable class="parameter">column_name</replaceable> TO <replaceable class="parameter">new_column_name</replaceable> +ALTER FOREIGN TABLE [ IF EXISTS ] <replaceable class="parameter">name</replaceable> + RENAME TO <replaceable class="parameter">new_name</replaceable> +ALTER FOREIGN TABLE [ IF EXISTS ] <replaceable class="parameter">name</replaceable> + SET SCHEMA <replaceable class="parameter">new_schema</replaceable> + +<phrase>where <replaceable class="parameter">action</replaceable> is one of:</phrase> + + ADD [ COLUMN ] <replaceable class="parameter">column_name</replaceable> <replaceable class="parameter">data_type</replaceable> [ COLLATE <replaceable class="parameter">collation</replaceable> ] [ <replaceable class="parameter">column_constraint</replaceable> [ ... ] ] + DROP [ COLUMN ] [ IF EXISTS ] <replaceable class="parameter">column_name</replaceable> [ RESTRICT | CASCADE ] + ALTER [ COLUMN ] <replaceable class="parameter">column_name</replaceable> [ SET DATA ] TYPE <replaceable class="parameter">data_type</replaceable> [ COLLATE <replaceable class="parameter">collation</replaceable> ] + ALTER [ COLUMN ] <replaceable class="parameter">column_name</replaceable> SET DEFAULT <replaceable class="parameter">expression</replaceable> + ALTER [ COLUMN ] <replaceable class="parameter">column_name</replaceable> DROP DEFAULT + ALTER [ COLUMN ] <replaceable class="parameter">column_name</replaceable> { SET | DROP } NOT NULL + ALTER [ COLUMN ] <replaceable class="parameter">column_name</replaceable> SET STATISTICS <replaceable class="parameter">integer</replaceable> + ALTER [ COLUMN ] <replaceable class="parameter">column_name</replaceable> SET ( <replaceable class="parameter">attribute_option</replaceable> = <replaceable class="parameter">value</replaceable> [, ... ] ) + ALTER [ COLUMN ] <replaceable class="parameter">column_name</replaceable> RESET ( <replaceable class="parameter">attribute_option</replaceable> [, ... ] ) + ALTER [ COLUMN ] <replaceable class="parameter">column_name</replaceable> SET STORAGE { PLAIN | EXTERNAL | EXTENDED | MAIN } + ALTER [ COLUMN ] <replaceable class="parameter">column_name</replaceable> OPTIONS ( [ ADD | SET | DROP ] <replaceable class="parameter">option</replaceable> ['<replaceable class="parameter">value</replaceable>'] [, ... ]) + ADD <replaceable class="parameter">table_constraint</replaceable> [ NOT VALID ] + VALIDATE CONSTRAINT <replaceable class="parameter">constraint_name</replaceable> + DROP CONSTRAINT [ IF EXISTS ] <replaceable class="parameter">constraint_name</replaceable> [ RESTRICT | CASCADE ] + DISABLE TRIGGER [ <replaceable class="parameter">trigger_name</replaceable> | ALL | USER ] + ENABLE TRIGGER [ <replaceable class="parameter">trigger_name</replaceable> | ALL | USER ] + ENABLE REPLICA TRIGGER <replaceable class="parameter">trigger_name</replaceable> + ENABLE ALWAYS TRIGGER <replaceable class="parameter">trigger_name</replaceable> + SET WITHOUT OIDS + INHERIT <replaceable class="parameter">parent_table</replaceable> + NO INHERIT <replaceable class="parameter">parent_table</replaceable> + OWNER TO { <replaceable class="parameter">new_owner</replaceable> | CURRENT_ROLE | CURRENT_USER | SESSION_USER } + OPTIONS ( [ ADD | SET | DROP ] <replaceable class="parameter">option</replaceable> ['<replaceable class="parameter">value</replaceable>'] [, ... ]) +</synopsis> + </refsynopsisdiv> + + <refsect1> + <title>Description</title> + + <para> + <command>ALTER FOREIGN TABLE</command> changes the definition of an + existing foreign table. There are several subforms: + + <variablelist> + <varlistentry> + <term><literal>ADD COLUMN</literal></term> + <listitem> + <para> + This form adds a new column to the foreign table, using the same syntax as + <link linkend="sql-createforeigntable"><command>CREATE FOREIGN TABLE</command></link>. + Unlike the case when adding a column to a regular table, nothing happens + to the underlying storage: this action simply declares that + some new column is now accessible through the foreign table. + </para> + </listitem> + </varlistentry> + + <varlistentry> + <term><literal>DROP COLUMN [ IF EXISTS ]</literal></term> + <listitem> + <para> + This form drops a column from a foreign table. + You will need to say <literal>CASCADE</literal> if + anything outside the table depends on the column; for example, + views. + If <literal>IF EXISTS</literal> is specified and the column + does not exist, no error is thrown. In this case a notice + is issued instead. + </para> + </listitem> + </varlistentry> + + <varlistentry> + <term><literal>SET DATA TYPE</literal></term> + <listitem> + <para> + This form changes the type of a column of a foreign table. + Again, this has no effect on any underlying storage: this action simply + changes the type that <productname>PostgreSQL</productname> believes the column to + have. + </para> + </listitem> + </varlistentry> + + <varlistentry> + <term><literal>SET</literal>/<literal>DROP DEFAULT</literal></term> + <listitem> + <para> + These forms set or remove the default value for a column. + Default values only apply in subsequent <command>INSERT</command> + or <command>UPDATE</command> commands; they do not cause rows already in the + table to change. + </para> + </listitem> + </varlistentry> + + <varlistentry> + <term><literal>SET</literal>/<literal>DROP NOT NULL</literal></term> + <listitem> + <para> + Mark a column as allowing, or not allowing, null values. + </para> + </listitem> + </varlistentry> + + <varlistentry> + <term><literal>SET STATISTICS</literal></term> + <listitem> + <para> + This form + sets the per-column statistics-gathering target for subsequent + <link linkend="sql-analyze"><command>ANALYZE</command></link> operations. + See the similar form of <link linkend="sql-altertable"><command>ALTER TABLE</command></link> + for more details. + </para> + </listitem> + </varlistentry> + + <varlistentry> + <term><literal>SET ( <replaceable class="parameter">attribute_option</replaceable> = <replaceable class="parameter">value</replaceable> [, ... ] )</literal></term> + <term><literal>RESET ( <replaceable class="parameter">attribute_option</replaceable> [, ... ] )</literal></term> + <listitem> + <para> + This form sets or resets per-attribute options. + See the similar form of <link linkend="sql-altertable"><command>ALTER TABLE</command></link> + for more details. + </para> + </listitem> + </varlistentry> + + <varlistentry> + <term> + <literal>SET STORAGE</literal> + </term> + <listitem> + <para> + This form sets the storage mode for a column. + See the similar form of <link linkend="sql-altertable"><command>ALTER TABLE</command></link> + for more details. + Note that the storage mode has no effect unless the table's + foreign-data wrapper chooses to pay attention to it. + </para> + </listitem> + </varlistentry> + + <varlistentry> + <term><literal>ADD <replaceable class="parameter">table_constraint</replaceable> [ NOT VALID ]</literal></term> + <listitem> + <para> + This form adds a new constraint to a foreign table, using the same + syntax as <link linkend="sql-createforeigntable"><command>CREATE FOREIGN TABLE</command></link>. + Currently only <literal>CHECK</literal> constraints are supported. + </para> + + <para> + Unlike the case when adding a constraint to a regular table, nothing is + done to verify the constraint is correct; rather, this action simply + declares that some new condition should be assumed to hold for all rows + in the foreign table. (See the discussion + in <link linkend="sql-createforeigntable"><command>CREATE FOREIGN TABLE</command></link>.) + If the constraint is marked <literal>NOT VALID</literal>, then it isn't + assumed to hold, but is only recorded for possible future use. + </para> + </listitem> + </varlistentry> + + <varlistentry> + <term><literal>VALIDATE CONSTRAINT</literal></term> + <listitem> + <para> + This form marks as valid a constraint that was previously marked + as <literal>NOT VALID</literal>. No action is taken to verify the + constraint, but future queries will assume that it holds. + </para> + </listitem> + </varlistentry> + + <varlistentry> + <term><literal>DROP CONSTRAINT [ IF EXISTS ]</literal></term> + <listitem> + <para> + This form drops the specified constraint on a foreign table. + If <literal>IF EXISTS</literal> is specified and the constraint + does not exist, no error is thrown. + In this case a notice is issued instead. + </para> + </listitem> + </varlistentry> + + <varlistentry> + <term><literal>DISABLE</literal>/<literal>ENABLE [ REPLICA | ALWAYS ] TRIGGER</literal></term> + <listitem> + <para> + These forms configure the firing of trigger(s) belonging to the foreign + table. See the similar form of <link linkend="sql-altertable"><command>ALTER TABLE</command></link> for more + details. + </para> + </listitem> + </varlistentry> + + <varlistentry> + <term><literal>SET WITHOUT OIDS</literal></term> + <listitem> + <para> + Backward compatibility syntax for removing the <literal>oid</literal> + system column. As <literal>oid</literal> system columns cannot be added + anymore, this never has an effect. + </para> + </listitem> + </varlistentry> + + <varlistentry> + <term><literal>INHERIT <replaceable class="parameter">parent_table</replaceable></literal></term> + <listitem> + <para> + This form adds the target foreign table as a new child of the specified + parent table. + See the similar form of <link linkend="sql-altertable"><command>ALTER TABLE</command></link> + for more details. + </para> + </listitem> + </varlistentry> + + <varlistentry> + <term><literal>NO INHERIT <replaceable class="parameter">parent_table</replaceable></literal></term> + <listitem> + <para> + This form removes the target foreign table from the list of children of + the specified parent table. + </para> + </listitem> + </varlistentry> + + <varlistentry> + <term><literal>OWNER</literal></term> + <listitem> + <para> + This form changes the owner of the foreign table to the + specified user. + </para> + </listitem> + </varlistentry> + + <varlistentry> + <term><literal>OPTIONS ( [ ADD | SET | DROP ] <replaceable class="parameter">option</replaceable> ['<replaceable class="parameter">value</replaceable>'] [, ... ] )</literal></term> + <listitem> + <para> + Change options for the foreign table or one of its columns. + <literal>ADD</literal>, <literal>SET</literal>, and <literal>DROP</literal> + specify the action to be performed. <literal>ADD</literal> is assumed + if no operation is explicitly specified. Duplicate option names are not + allowed (although it's OK for a table option and a column option to have + the same name). Option names and values are also validated using the + foreign data wrapper library. + </para> + </listitem> + </varlistentry> + + <varlistentry> + <term><literal>RENAME</literal></term> + <listitem> + <para> + The <literal>RENAME</literal> forms change the name of a foreign table + or the name of an individual column in a foreign table. + </para> + </listitem> + </varlistentry> + + <varlistentry> + <term><literal>SET SCHEMA</literal></term> + <listitem> + <para> + This form moves the foreign table into another schema. + </para> + </listitem> + </varlistentry> + + </variablelist> + </para> + + <para> + All the actions except <literal>RENAME</literal> and <literal>SET SCHEMA</literal> + can be combined into + a list of multiple alterations to apply in parallel. For example, it + is possible to add several columns and/or alter the type of several + columns in a single command. + </para> + + <para> + If the command is written as <literal>ALTER FOREIGN TABLE IF EXISTS ...</literal> + and the foreign table does not exist, no error is thrown. A notice is + issued in this case. + </para> + + <para> + You must own the table to use <command>ALTER FOREIGN TABLE</command>. + To change the schema of a foreign table, you must also have + <literal>CREATE</literal> privilege on the new schema. + To alter the owner, you must also be a direct or indirect member of the new + owning role, and that role must have <literal>CREATE</literal> privilege on + the table's schema. (These restrictions enforce that altering the owner + doesn't do anything you couldn't do by dropping and recreating the table. + However, a superuser can alter ownership of any table anyway.) + To add a column or alter a column type, you must also + have <literal>USAGE</literal> privilege on the data type. + </para> + </refsect1> + + <refsect1> + <title>Parameters</title> + + <variablelist> + + <varlistentry> + <term><replaceable class="parameter">name</replaceable></term> + <listitem> + <para> + The name (possibly schema-qualified) of an existing foreign table to + alter. If <literal>ONLY</literal> is specified before the table name, only + that table is altered. If <literal>ONLY</literal> is not specified, the table + and all its descendant tables (if any) are altered. Optionally, + <literal>*</literal> can be specified after the table name to explicitly + indicate that descendant tables are included. + </para> + </listitem> + </varlistentry> + + <varlistentry> + <term><replaceable class="parameter">column_name</replaceable></term> + <listitem> + <para> + Name of a new or existing column. + </para> + </listitem> + </varlistentry> + + <varlistentry> + <term><replaceable class="parameter">new_column_name</replaceable></term> + <listitem> + <para> + New name for an existing column. + </para> + </listitem> + </varlistentry> + + <varlistentry> + <term><replaceable class="parameter">new_name</replaceable></term> + <listitem> + <para> + New name for the table. + </para> + </listitem> + </varlistentry> + + <varlistentry> + <term><replaceable class="parameter">data_type</replaceable></term> + <listitem> + <para> + Data type of the new column, or new data type for an existing + column. + </para> + </listitem> + </varlistentry> + + <varlistentry> + <term><replaceable class="parameter">table_constraint</replaceable></term> + <listitem> + <para> + New table constraint for the foreign table. + </para> + </listitem> + </varlistentry> + + <varlistentry> + <term><replaceable class="parameter">constraint_name</replaceable></term> + <listitem> + <para> + Name of an existing constraint to drop. + </para> + </listitem> + </varlistentry> + + <varlistentry> + <term><literal>CASCADE</literal></term> + <listitem> + <para> + Automatically drop objects that depend on the dropped column + or constraint (for example, views referencing the column), + and in turn all objects that depend on those objects + (see <xref linkend="ddl-depend"/>). + </para> + </listitem> + </varlistentry> + + <varlistentry> + <term><literal>RESTRICT</literal></term> + <listitem> + <para> + Refuse to drop the column or constraint if there are any dependent + objects. This is the default behavior. + </para> + </listitem> + </varlistentry> + + <varlistentry> + <term><replaceable class="parameter">trigger_name</replaceable></term> + <listitem> + <para> + Name of a single trigger to disable or enable. + </para> + </listitem> + </varlistentry> + + <varlistentry> + <term><literal>ALL</literal></term> + <listitem> + <para> + Disable or enable all triggers belonging to the foreign table. (This + requires superuser privilege if any of the triggers are internally + generated triggers. The core system does not add such triggers to + foreign tables, but add-on code could do so.) + </para> + </listitem> + </varlistentry> + + <varlistentry> + <term><literal>USER</literal></term> + <listitem> + <para> + Disable or enable all triggers belonging to the foreign table except + for internally generated triggers. + </para> + </listitem> + </varlistentry> + + <varlistentry> + <term><replaceable class="parameter">parent_table</replaceable></term> + <listitem> + <para> + A parent table to associate or de-associate with this foreign table. + </para> + </listitem> + </varlistentry> + + <varlistentry> + <term><replaceable class="parameter">new_owner</replaceable></term> + <listitem> + <para> + The user name of the new owner of the table. + </para> + </listitem> + </varlistentry> + + <varlistentry> + <term><replaceable class="parameter">new_schema</replaceable></term> + <listitem> + <para> + The name of the schema to which the table will be moved. + </para> + </listitem> + </varlistentry> + </variablelist> + </refsect1> + + <refsect1> + <title>Notes</title> + + <para> + The key word <literal>COLUMN</literal> is noise and can be omitted. + </para> + + <para> + Consistency with the foreign server is not checked when a column is added + or removed with <literal>ADD COLUMN</literal> or + <literal>DROP COLUMN</literal>, a <literal>NOT NULL</literal> + or <literal>CHECK</literal> constraint is added, or a column type is changed + with <literal>SET DATA TYPE</literal>. It is the user's responsibility to ensure + that the table definition matches the remote side. + </para> + + <para> + Refer to <link linkend="sql-createforeigntable"><command>CREATE FOREIGN TABLE</command></link> for a further description of valid + parameters. + </para> + </refsect1> + + <refsect1> + <title>Examples</title> + + <para> + To mark a column as not-null: +<programlisting> +ALTER FOREIGN TABLE distributors ALTER COLUMN street SET NOT NULL; +</programlisting> + </para> + + <para> + To change options of a foreign table: +<programlisting> +ALTER FOREIGN TABLE myschema.distributors OPTIONS (ADD opt1 'value', SET opt2 'value2', DROP opt3); +</programlisting></para> + + </refsect1> + + <refsect1> + <title>Compatibility</title> + + <para> + The forms <literal>ADD</literal>, <literal>DROP</literal>, + and <literal>SET DATA TYPE</literal> + conform with the SQL standard. The other forms are + <productname>PostgreSQL</productname> extensions of the SQL standard. + Also, the ability to specify more than one manipulation in a single + <command>ALTER FOREIGN TABLE</command> command is an extension. + </para> + + <para> + <command>ALTER FOREIGN TABLE DROP COLUMN</command> can be used to drop the only + column of a foreign table, leaving a zero-column table. This is an + extension of SQL, which disallows zero-column foreign tables. + </para> + </refsect1> + + <refsect1> + <title>See Also</title> + + <simplelist type="inline"> + <member><xref linkend="sql-createforeigntable"/></member> + <member><xref linkend="sql-dropforeigntable"/></member> + </simplelist> + </refsect1> +</refentry> |