Skip to content
体验新版
项目
组织
正在加载...
登录
切换导航
打开侧边栏
Greenplum
Gpdb
提交
ecc367b7
G
Gpdb
项目概览
Greenplum
/
Gpdb
通知
7
Star
1
Fork
0
代码
文件
提交
分支
Tags
贡献者
分支图
Diff
Issue
0
列表
看板
标记
里程碑
合并请求
0
DevOps
流水线
流水线任务
计划
Wiki
0
Wiki
分析
仓库
DevOps
项目成员
Pages
G
Gpdb
项目概览
项目概览
详情
发布
仓库
仓库
文件
提交
分支
标签
贡献者
分支图
比较
Issue
0
Issue
0
列表
看板
标记
里程碑
合并请求
0
合并请求
0
Pages
DevOps
DevOps
流水线
流水线任务
计划
分析
分析
仓库分析
DevOps
Wiki
0
Wiki
成员
成员
收起侧边栏
关闭侧边栏
动态
分支图
创建新Issue
流水线任务
提交
Issue看板
体验新版 GitCode,发现更多精彩内容 >>
提交
ecc367b7
编写于
11月 11, 2000
作者:
T
Thomas G. Lockhart
浏览文件
操作
浏览文件
下载
电子邮件补丁
差异文件
Mention new AT TIME ZONE feature.
上级
bc20c412
变更
1
隐藏空白更改
内联
并排
Showing
1 changed file
with
40 addition
and
19 deletion
+40
-19
doc/src/sgml/datatype.sgml
doc/src/sgml/datatype.sgml
+40
-19
未找到文件。
doc/src/sgml/datatype.sgml
浏览文件 @
ecc367b7
<!--
$Header: /cvsroot/pgsql/doc/src/sgml/datatype.sgml,v 1.
39 2000/11/10 20:13:25 tgl
Exp $
$Header: /cvsroot/pgsql/doc/src/sgml/datatype.sgml,v 1.
40 2000/11/11 19:50:31 thomas
Exp $
-->
<chapter id="datatype">
...
...
@@ -1248,29 +1248,34 @@ January 8 04:05:06 1999 PST
Although the <type>date</type> type
does not have an associated time zone, the
<type>time</type> type can or does.
Time zones in the real world can have no meaning unless
associated with a date as well as a time
since the offset may vary through the year with daylight savings
time boundaries.
</para>
</listitem>
<listitem>
<para>
The default time zone is specified as a constant integer offset
from GMT/UTC.
from GMT/UTC. It is not possible to adapt to daylight savings
time when doing date/time arithmetic across
<acronym>DST</acronym> boundaries.
</para>
</listitem>
</itemizedlist>
Time zones in the real world can have no meaning unless
associated with a date as well as a time
since the offset may vary through the year with daylight savings
time boundaries.
</para>
<para>
To address these difficulties, <productname>Postgres</productname>
associates time zones only with date and time
types which contain both date and time,
and assumes local time for any type containing only
To address these difficulties, we recommend using date/time
types which contain both date and time when using time zones. We
recommend <emphasis>not</emphasis> using the SQL92 type TIME
WITH TIME ZONE (though it is supported by
<productname>Postgres</productname> for legacy applications and
for compatibility with other RDBMS implementations).
<productname>Postgres</productname>
assumes local time for any type containing only
date or time. Further, time zone support is derived from
the underlying operating system
time zone capabilities, and hence can handle daylight savings time
...
...
@@ -1286,8 +1291,8 @@ January 8 04:05:06 1999 PST
</para>
<para>
All dates and times are stored internally in U
niversal U
TC,
alternate
ly known as Greenwich Mean Time (GMT).
All dates and times are stored internally in UTC,
traditional
ly known as Greenwich Mean Time (GMT).
Times are converted to local time on the database server before being
sent to the client frontend, hence by default are in the server
time zone.
...
...
@@ -1299,7 +1304,7 @@ January 8 04:05:06 1999 PST
<itemizedlist spacing="compact" mark="bullet">
<listitem>
<para>
The TZ environment variable used by the backend directly
The TZ environment variable
is
used by the backend directly
on postmaster start-up as the default time zone.
</para>
</listitem>
...
...
@@ -1315,15 +1320,27 @@ January 8 04:05:06 1999 PST
sets the time zone for the session.
</para>
</listitem>
<listitem>
<para>
The <acronym>SQL92</acronym> qualifier on
<programlisting>
<replaceable>timestamp</replaceable> AT TIME ZONE '<replaceable>zone</replaceable>'
</programlisting>
where <replaceable>zone</replaceable> can be specified as a
text time zone (e.g. <literal>'PST'</literal>) or as an
interval (e.g. <literal>INTERVAL '-08:00'</literal>).
</para>
</listitem>
</itemizedlist>
</para>
<para>
If an invalid time zone is specified,
the time zone becomes GMT (on most systems anyway).
</para>
<para>
<note>
<para>
If an invalid time zone is specified,
the time zone becomes GMT (on most systems anyway).
</para>
</note>
<note>
<para>
...
...
@@ -1889,6 +1906,10 @@ January 8 04:05:06 1999 PST
</tgroup>
</table>
</para>
</sect2>
<sect2 id="inet-type">
<title><type>inet</type></title>
<para>
The essential difference between <type>inet</type> and <type>cidr</type>
...
...
编辑
预览
Markdown
is supported
0%
请重试
或
添加新附件
.
添加附件
取消
You are about to add
0
people
to the discussion. Proceed with caution.
先完成此消息的编辑!
取消
想要评论请
注册
或
登录