database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-07-28 23:42:10 +03:00
Code Activity

Fix ALTER SEQUENCE so that it does not affect the value of currval() for

Browse Source 
the sequence.  Also, make setval() with is_called = false not affect the
currval state, either.  Per report from Kris Jurka that an implicit
ALTER SEQUENCE OWNED BY unexpectedly caused currval() to become valid.
Since this isn't 100% backwards compatible, it will go into HEAD only;
I'll put a more limited patch into 8.2.
This commit is contained in:
Tom Lane
2007-10-25 18:54:03 +00:00
parent dbe48765cd
commit 9ddfe034c7
3 changed files with 49 additions and 24 deletions
Download Patch File Download Diff File Expand all files Collapse all files

23
doc/src/sgml/func.sgml
View File

@ -1,4 +1,4 @@
<!-- $PostgreSQL: pgsql/doc/src/sgml/func.sgml,v 1.404 2007/10/23 20:46:11 tgl Exp $ -->
<!-- $PostgreSQL: pgsql/doc/src/sgml/func.sgml,v 1.405 2007/10/25 18:54:03 tgl Exp $ -->
<chapter id="functions">
<title>Functions and Operators</title>
@ -8733,15 +8733,20 @@ nextval('foo'::text) <lineannotation><literal>foo</literal> is looked up at
<listitem>
<para>
Reset the sequence object's counter value. The two-parameter
form sets the sequence's <literal>last_value</literal> field to the specified
value and sets its <literal>is_called</literal> field to <literal>true</literal>,
meaning that the next <function>nextval</function> will advance the sequence
before returning a value. In the three-parameter form,
<literal>is_called</literal> can be set either <literal>true</literal> or
<literal>false</literal>. If it's set to <literal>false</literal>,
the next <function>nextval</function> will return exactly the specified
form sets the sequence's <literal>last_value</literal> field to the
specified value and sets its <literal>is_called</literal> field to
<literal>true</literal>, meaning that the next
<function>nextval</function> will advance the sequence before
returning a value. The value reported by <function>currval</> is
also set to the specified value. In the three-parameter form,
<literal>is_called</literal> can be set either <literal>true</literal>
or <literal>false</literal>. <literal>true</> has the same effect as
the two-parameter form. If it's set to <literal>false</literal>, the
next <function>nextval</function> will return exactly the specified
value, and sequence advancement commences with the following
<function>nextval</function>. For example,
<function>nextval</function>. Furthermore, the value reported by
<function>currval</> is not changed in this case (this is a change
from pre-8.3 behavior). For example,
<screen>
SELECT setval('foo', 42); <lineannotation>Next <function>nextval</> will return 43</lineannotation>

13
doc/src/sgml/ref/alter_sequence.sgml
View File

@ -1,5 +1,5 @@
<!--
$PostgreSQL: pgsql/doc/src/sgml/ref/alter_sequence.sgml,v 1.18 2007/10/03 16:48:43 tgl Exp $
$PostgreSQL: pgsql/doc/src/sgml/ref/alter_sequence.sgml,v 1.19 2007/10/25 18:54:03 tgl Exp $
PostgreSQL documentation
-->
@ -114,7 +114,10 @@ ALTER SEQUENCE <replaceable class="parameter">name</replaceable> SET SCHEMA <rep
<para>
The optional clause <literal>RESTART WITH <replaceable
class="parameter">start</replaceable></literal> changes the
current value of the sequence.
current value of the sequence. This is equivalent to calling the
<function>setval</> function with <literal>is_called</literal> =
<literal>false</>: the specified value will be returned by the
<emphasis>next</> call of <function>nextval</>.
</para>
</listitem>
</varlistentry>
@ -226,6 +229,12 @@ ALTER SEQUENCE <replaceable class="parameter">name</replaceable> SET SCHEMA <rep
immediately.
</para>
<para>
<command>ALTER SEQUENCE</command> does not affect the <function>currval</>
status for the sequence. (Before <productname>PostgreSQL</productname>
8.3, it sometimes did.)
</para>
<para>
Some variants of <command>ALTER TABLE</command> can be used with
sequences as well; for example, to rename a sequence it is also