index eedb91d954dbd413904cfea1182681f72457143f..cf743aa2f769602c8d1a6104c52b348faff6818c 100644 (file)
<listitem>
<!--
+2016年12月20日 [1753b1b02] Add pg_sequence system catalog
+2016年11月18日 [67dc4ccbb] Add pg_sequences view
+2017年05月15日 [f8dc1985f] Fix ALTER SEQUENCE locking
+2017年06月01日 [3d79013b9] Make ALTER SEQUENCE, including RESTART, fully transactio
+-->
+ <para>
+ Move sequences' metadata fields into a new <link
+ linkend="catalog-pg-sequence"><structname>pg_sequence</></>
+ system catalog (Peter Eisentraut)
+ </para>
+
+ <para>
+ A sequence relation now stores only the fields that can be modified
+ by <function>nextval()</>, that
+ is <structfield>last_value</>, <structfield>log_cnt</>,
+ and <structfield>is_called</>. Other sequence properties, such as
+ the starting value and increment, are kept in a corresponding row of
+ the <structname>pg_sequence</> catalog.
+ <command>ALTER SEQUENCE</> updates are now fully transactional,
+ implying that the sequence is locked until commit.
+ The <function>nextval()</> and <function>setval()</> functions
+ remain nontransactional.
+ </para>
+
+ <para>
+ The main incompatibility introduced by this change is that selecting
+ from a sequence relation now returns only the three fields named
+ above. To obtain the sequence's other properties, applications must
+ look into <structname>pg_sequence</>. The new system
+ view <link linkend="view-pg-sequences"><structname>pg_sequences</></>
+ can also be used for this purpose; it provides column names that are
+ more compatible with existing code.
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
2017年01月04日 [9a4d51077] Make wal streaming the default mode for pg_basebackup
-->
<para>
<listitem>
<!--
-2016年12月20日 [1753b1b02] Add pg_sequence system catalog
-2016年11月18日 [67dc4ccbb] Add pg_sequences view
-2017年05月15日 [f8dc1985f] Fix ALTER SEQUENCE locking
-2017年06月01日 [3d79013b9] Make ALTER SEQUENCE, including RESTART, fully transactio
--->
- <para>
- Create a <link
- linkend="catalog-pg-sequence"><structname>pg_sequence</></>
- system catalog to store sequence metadata (Peter Eisentraut)
- </para>
-
- <para>
- Sequence metadata includes the start, increment, etc, properties.
- <command>ALTER SEQUENCE</> updates are now fully transactional,
- implying that the sequence is locked until commit. Sequences'
- current values are still stored in individual table files, and
- the <function>nextval()</> and <function>setval()</> functions
- remain nontransactional.
- </para>
-
- <para>
- Also
- add <link linkend="view-pg-sequences"><structname>pg_sequences</></>
- view to show all sequences.
- </para>
- </listitem>
-
- <listitem>
-<!--
2017年03月08日 [f9b1a0dd4] Expose explain's SUMMARY option
-->
<para>