From 78ec1cb0277307cb6f8c12e5bd5aae0fa2cb3493 Mon Sep 17 00:00:00 2001
From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Sun, 23 Dec 2001 20:21:37 +0000
Subject: [PATCH] Type interval takes a precision, too.
---
doc/src/sgml/datatype.sgml | 33 ++++++++++++++++++++++-----------
1 file changed, 22 insertions(+), 11 deletions(-)
diff --git a/doc/src/sgml/datatype.sgml b/doc/src/sgml/datatype.sgml
index 26eeb60c276..45d14306ccd 100644
--- a/doc/src/sgml/datatype.sgml
+++ b/doc/src/sgml/datatype.sgml
@@ -1,5 +1,5 @@
<!--
-$Header: /cvsroot/pgsql/doc/src/sgml/datatype.sgml,v 1.79 2001/12/21 03:54:02 thomas Exp $
+$Header: /cvsroot/pgsql/doc/src/sgml/datatype.sgml,v 1.80 2001/12/23 20:21:37 tgl Exp $
-->
<chapter id="datatype">
@@ -1290,7 +1290,7 @@ SELECT b, char_length(b) FROM test2;
<entry>1 microsecond / 14 digits</entry>
</row>
<row>
- <entry><type>interval</type></entry>
+ <entry><type>interval [ (<replaceable>p</replaceable>) ]</type></entry>
<entry>for time intervals</entry>
<entry>12 bytes</entry>
<entry>-178000000 years</entry>
@@ -1327,14 +1327,19 @@ SELECT b, char_length(b) FROM test2;
</para>
<para>
- <type>time</type> and <type>timestamp</type> both accept an
- optional precision field <replaceable>p</replaceable> which
- determines the number of digits retained beyond the seconds
- decimal point. By default, there is no explicit bound on precision
- and the actual precision is determined by the underlying double
- precision floating point number used to store values in seconds
+ <type>time</type>, <type>timestamp</type>, and <type>interval</type>
+ accept an
+ optional precision value <replaceable>p</replaceable> which
+ specifies the number of fractional digits retained in the seconds
+ field. By default, there is no explicit bound on precision. The
+ effective limit of precision is determined by the underlying double
+ precision floating point number used to store values (in seconds
for <type>interval</type> and
- in seconds since 2000-01-01 for <type>timestamp</type>.
+ in seconds since 2000-01-01 for <type>timestamp</type>). The
+ useful range of <replaceable>p</replaceable> is from 0 to about
+ 6 for <type>timestamp</type>, but may be more for <type>interval</type>.
+ The system will accept <replaceable>p</replaceable> ranging from
+ 0 to 13.
</para>
<para>
@@ -1846,7 +1851,7 @@ January 8 04:05:06 1999 PST
</sect3>
<sect3>
- <title><type>interval</type></title>
+ <title><type>interval [ ( <replaceable>precision</replaceable> ) ]</type></title>
<indexterm>
<primary>interval</primary>
@@ -1860,7 +1865,7 @@ January 8 04:05:06 1999 PST
@ Quantity Unit [Quantity Unit...] [Direction]
</programlisting>
- where: <literal>Quantity</literal> is an integer (possibly signed);
+ where: <literal>Quantity</literal> is a number (possibly signed),
<literal>Unit</literal> is <literal>second</literal>,
<literal>minute</literal>, <literal>hour</literal>, <literal>day</literal>,
<literal>week</literal>, <literal>month</literal>, <literal>year</literal>,
@@ -1877,6 +1882,12 @@ January 8 04:05:06 1999 PST
explicit unit markings. For example, <literal>'1 12:59:10'</> is read
the same as <literal>'1 day 12 hours 59 min 10 sec'</>.
</para>
+
+ <para>
+ The optional precision
+ <replaceable>p</replaceable> should be between 0 and 13, and
+ defaults to the precision of the input literal.
+ </para>
</sect3>
<sect3>
--
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