database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-12-21 05:21:08 +03:00
Code Activity

Change the rules for inherited CHECK constraints to be essentially the same

Browse Source 
as those for inherited columns; that is, it's no longer allowed for a child
table to not have a check constraint matching one that exists on a parent.
This satisfies the principle of least surprise (rows selected from the parent
will always appear to meet its check constraints) and eliminates some
longstanding bogosity in pg_dump, which formerly had to guess about whether
check constraints were really inherited or not.

The implementation involves adding conislocal and coninhcount columns to
pg_constraint (paralleling attislocal and attinhcount in pg_attribute)
and refactoring various ALTER TABLE actions to be more like those for
columns.

Alex Hunsaker, Nikhil Sontakke, Tom Lane
This commit is contained in:
Tom Lane
2008-05-09 23:32:05 +00:00
parent f8df836ae3
commit cd902b331d
25 changed files with 1391 additions and 575 deletions
Download Patch File Download Diff File Expand all files Collapse all files

7
doc/src/sgml/ddl.sgml
View File

@@ -1,4 +1,4 @@
<!-- $PostgreSQL: pgsql/doc/src/sgml/ddl.sgml,v 1.81 2008/01/13 17:58:54 tgl Exp $ -->
<!-- $PostgreSQL: pgsql/doc/src/sgml/ddl.sgml,v 1.82 2008/05/09 23:32:03 tgl Exp $ -->
<chapter id="ddl">
<title>Data Definition</title>
@@ -2107,7 +2107,8 @@ VALUES ('New York', NULL, NULL, 'NY');
<para>
A parent table cannot be dropped while any of its children remain. Neither
can columns of child tables be dropped or altered if they are inherited
can columns or check constraints of child tables be dropped or altered
if they are inherited
from any parent tables. If you wish to remove a table and all of its
descendants, one easy way is to drop the parent table with the
<literal>CASCADE</literal> option.
@@ -2117,7 +2118,7 @@ VALUES ('New York', NULL, NULL, 'NY');
<xref linkend="sql-altertable" endterm="sql-altertable-title"> will
propagate any changes in column data definitions and check
constraints down the inheritance hierarchy. Again, dropping
columns or constraints on parent tables is only possible when using
columns that are depended on by other tables is only possible when using
the <literal>CASCADE</literal> option. <command>ALTER
TABLE</command> follows the same rules for duplicate column merging
and rejection that apply during <command>CREATE TABLE</command>.