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Second phase of committing Rod Taylor's pg_depend/pg_constraint patch.

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pg_relcheck is gone; CHECK, UNIQUE, PRIMARY KEY, and FOREIGN KEY
constraints all have real live entries in pg_constraint.  pg_depend
exists, and RESTRICT/CASCADE options work on most kinds of DROP;
however, pg_depend is not yet very well populated with dependencies.
(Most of the ones that are present at this point just replace formerly
hardwired associations, such as the implicit drop of a relation's pg_type
entry when the relation is dropped.)  Need to add more logic to create
dependency entries, improve pg_dump to dump constraints in place of
indexes and triggers, and add some regression tests.
This commit is contained in:
Tom Lane
2002-07-12 18:43:19 +00:00
parent 791a40f943
commit 7c6df91dda
77 changed files with 4074 additions and 1987 deletions
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26
doc/src/sgml/ref/alter_table.sgml
View File

@@ -1,5 +1,5 @@
<!--
$Header: /cvsroot/pgsql/doc/src/sgml/ref/alter_table.sgml,v 1.45 2002/05/18 15:44:47 petere Exp $
$Header: /cvsroot/pgsql/doc/src/sgml/ref/alter_table.sgml,v 1.46 2002/07/12 18:43:12 tgl Exp $
PostgreSQL documentation
-->
@@ -39,7 +39,7 @@ ALTER TABLE <replaceable class="PARAMETER">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>
DROP CONSTRAINT <replaceable class="PARAMETER">constraint_name</replaceable> { RESTRICT | CASCADE }
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>
</synopsis>
@@ -315,26 +315,6 @@ ALTER TABLE <replaceable class="PARAMETER">table</replaceable>
form after you've entered non-null values for the column in all rows.
</para>
<para>
In DROP CONSTRAINT, the RESTRICT keyword is required, although
dependencies are not yet checked. The CASCADE option is unsupported.
Currently DROP CONSTRAINT only handles CHECK constraints.
To remove a PRIMARY or UNIQUE constraint, drop the
relevant index using the <xref linkend="SQL-DROPINDEX" endterm="sql-dropindex-title"> command.
To remove FOREIGN KEY constraints you need to recreate
and reload the table, using other parameters to the
<xref linkend="SQL-CREATETABLE" endterm="sql-createtable-title"> command.
</para>
<para>
For example, to drop all constraints on a table <literal>distributors</literal>:
<programlisting>
CREATE TABLE temp AS SELECT * FROM distributors;
DROP TABLE distributors;
CREATE TABLE distributors AS SELECT * FROM temp;
DROP TABLE temp;
</programlisting>
</para>
<para>
Changing any part of the schema of a system
catalog is not permitted.
@@ -395,7 +375,7 @@ ALTER TABLE distributors ADD CONSTRAINT zipchk CHECK (char_length(zipcode) = 5);
<para>
To remove a check constraint from a table and all its children:
<programlisting>
ALTER TABLE distributors DROP CONSTRAINT zipchk RESTRICT;
ALTER TABLE distributors DROP CONSTRAINT zipchk;
</programlisting>
</para>