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Add more documentation about CURRENT_TIMESTAMP.

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Also, code < and > as &lt;/&gt; for cleaner SGML.
This commit is contained in:
Bruce Momjian 2002-10-05 19:03:16 +00:00
parent 82df2dd732
commit 0c88e38eda
1 changed files with 16 additions and 11 deletions
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27
doc/src/sgml/func.sgml
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@ -1,5 +1,5 @@
<!--
$Header: /cvsroot/pgsql/doc/src/sgml/func.sgml,v 1.126 2002/09/24 20:14:58 petere Exp $
$Header: /cvsroot/pgsql/doc/src/sgml/func.sgml,v 1.127 2002/10/05 19:03:16 momjian Exp $
PostgreSQL documentation
-->
@ -491,11 +491,11 @@ PostgreSQL documentation
<entry>01110</entry>
</row>
<row>
<entry>B'10001' << 3</entry>
<entry>B'10001' &lt;&lt; 3</entry>
<entry>01000</entry>
</row>
<row>
<entry>B'10001' >> 2</entry>
<entry>B'10001' &gt;&gt; 2</entry>
<entry>00100</entry>
</row>
</tbody>
@ -2726,7 +2726,7 @@ SUBSTRING('foobar' FROM 'o(.)b') <lineannotation>o</lineannotation>
<para>
There are two special cases of bracket expressions: the bracket
expressions <literal>[[:<:]]</literal> and
expressions <literal>[[:&lt;:]]</literal> and
<literal>[[:>:]]</literal> match the null string at the beginning
and end of a word respectively. A word is defined as a sequence
of word characters which is neither preceded nor followed by word
@ -3277,11 +3277,11 @@ SUBSTRING('foobar' FROM 'o(.)b') <lineannotation>o</lineannotation>
</row>
<row>
<entry><literal>MI</literal></entry>
<entry>minus sign in specified position (if number < 0)</entry>
<entry>minus sign in specified position (if number &lt; 0)</entry>
</row>
<row>
<entry><literal>PL</literal></entry>
<entry>plus sign in specified position (if number > 0)</entry>
<entry>plus sign in specified position (if number &gt; 0)</entry>
</row>
<row>
<entry><literal>SG</literal></entry>
@ -4293,13 +4293,18 @@ SELECT timeofday();
</informalexample>
<para>
It is quite important to realize that
<function>CURRENT_TIMESTAMP</function> and related functions all return
the time as of the start of the current transaction; their values do not
increment while a transaction is running. But
<function>timeofday()</function> returns the actual current time.
It is important to realize that
<function>CURRENT_TIMESTAMP</function> and related functions return
the start time of the current transaction; their values do not
change during the transaction. <function>timeofday()</function>
returns the wall clock time and does advance during transactions.
</para>
<note>
Many other database systems advance these values more
frequently.
</note>
<para>
All the date/time data types also accept the special literal value
<literal>now</literal> to specify the current date and time. Thus,