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$Header: /cvsroot/pgsql/doc/src/sgml/ref/alter_table.sgml,v 1.50 2002/09/21 18:32:54 petere Exp $

$Header: /cvsroot/pgsql/doc/src/sgml/ref/alter_table.sgml,v 1.51 2002/10/19 22:51:45 tgl Exp $

PostgreSQL documentation

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class="PARAMETER">new_column</replaceable>

ALTER TABLE <replaceable class="PARAMETER">table</replaceable>

RENAME TO <replaceable class="PARAMETER">new_table</replaceable>

ALTER TABLE <replaceable class="PARAMETER">table</replaceable>

ADD <replaceable class="PARAMETER">table_constraint_definition</replaceable>

ALTER TABLE [ ONLY ] <replaceable class="PARAMETER">table</replaceable>

ALTER TABLE[ ONLY ]<replaceable class="PARAMETER">table</replaceable> [ * ]

ADD <replaceable class="PARAMETER">table_constraint</replaceable>

ALTER TABLE [ ONLY ] <replaceable class="PARAMETER">table</replaceable>[ * ]

DROP CONSTRAINT <replaceable class="PARAMETER">constraint_name</replaceable> [ RESTRICT | CASCADE ]

ALTER TABLE <replaceable class="PARAMETER">table</replaceable>

OWNER TO <replaceable class="PARAMETER">new_owner</replaceable>

</varlistentry>

<varlistentry>

<term><replaceable class="PARAMETER">table_constraint_definition </replaceable></term>

<term><replaceable class="PARAMETER">table_constraint </replaceable></term>

<listitem>

<para>

New table constraint for the table.

</varlistentry>

<varlistentry>

<term>ADD <replaceable class="PARAMETER">table_constraint_definition</replaceable></term>

<term>ADD <replaceable class="PARAMETER">table_constraint</replaceable></term>

<listitem>

<para>

This form adds a new constraint to a table using the same syntax as

<term>DROP CONSTRAINT</term>

<listitem>

<para>

This form drops constraints on a table (and its children).

This form drops constraints on a table.

Currently, constraints on tables are not required to have unique

names, so there may be more than one constraint matching the specified

name. All such constraints will be dropped.

</programlisting>

</para>

<para>

If a table has any descendant tables, it is not permitted to ADD or

RENAME a column in the parent table without doing the same to the

descendants --- that is, ALTER TABLE ONLY will be rejected. This

ensures that the descendants always have columns matching the parent.

</para>

<para>

A recursive DROP COLUMN operation will remove a descendant table's column

only if the descendant does not inherit that column from any other

parents and never had an independent definition of the column.

A nonrecursive DROP COLUMN (i.e., ALTER TABLE ONLY ... DROP COLUMN)

never removes any descendant columns, but instead marks them as

independently defined rather than inherited.

</para>

<para>

Changing any part of the schema of a system

catalog is not permitted.