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authorPeter Eisentraut2009-01-08 12:47:58 +0000
committerPeter Eisentraut2009-01-08 12:47:58 +0000
commit60eab2f46ac78690ebe76077fe08b0c6c83b7274 (patch)
treeb397aad9eac301bd49f51ce8cf730bc0f080911b
parentc1ea6ce3fffde81e185b7042da7f22159db8cec1 (diff)
Add note that not all SQL commands support ONLY in the same way.
-rw-r--r--doc/src/sgml/ddl.sgml17
1 files changed, 17 insertions, 0 deletions
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index aa8a103af6..d71a1cc262 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -2137,6 +2137,23 @@ VALUES ('New York', NULL, NULL, 'NY');
</para>
<para>
+ More generally, note that not all SQL commands are able to work on
+ inheritance hierarchies. Commands that are used for data querying,
+ data modification, or schema modification
+ (e.g., <literal>SELECT</literal>, <literal>UPDATE</literal>, <literal>DELETE</literal>,
+ most variants of <literal>ALTER TABLE</literal>, but
+ not <literal>INSERT</literal> and <literal>ALTER TABLE ...
+ RENAME</literal>) typically default to including child tables and
+ support the <literal>ONLY</literal> notation to exclude them.
+ Commands that do database maintenance and tuning
+ (e.g., <literal>REINDEX</literal>, <literal>VACUUM</literal>)
+ typically only work on individual, physical tables and do no
+ support recursing over inheritance hierarchies. The respective
+ behavior of each individual command is documented in the reference
+ part (<xref linkend="sql-commands">).
+ </para>
+
+ <para>
A serious limitation of the inheritance feature is that indexes (including
unique constraints) and foreign key constraints only apply to single
tables, not to their inheritance children. This is true on both the