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Try to clarify characteristics of the SERIAL type.
Fix source indenting, which does not affect output. Note: still need docs on NUMERIC and DECIMAL (and let's not talk about regression tests :()
This commit is contained in:
Thomas G. Lockhart
@ -265,7 +265,8 @@
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<para>
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Numeric types consist of two- and four-byte integers and four- and eight-byte
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floating point numbers.</para>
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floating point numbers.
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</para>
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<para>
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<table tocentry="1">
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@ -328,6 +329,14 @@ functions. Refer to <xref endterm="math-opers" linkend="math-opers">
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and <xref endterm="math-funcs" linkend="math-funcs"> for more information.
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</para>
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<para>
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The <type>int8</type> type may not be available on all platforms since
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it relies on compiler support for this.
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</para>
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<sect2>
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<title>The Serial Type</title>
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<para>
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The <type>serial</type> type is a special-case type constructed by
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<productname>Postgres</productname> from other existing components.
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@ -350,8 +359,14 @@ CREATE UNIQUE INDEX <replaceable class="parameter">tablename</replaceable>_<repl
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<caution>
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<para>
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The implicit sequence created for the <type>serial</type> type will
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<emphasis>not</emphasis> be automatically removed when the table is dropped.
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So, the following commands executed in order will likely fail:
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<emphasis>not</emphasis> be automatically removed when the
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table is dropped.
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</para>
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</caution>
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Implicit sequences supporting the <type>serial</type> are
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not automatically dropped when a table containing a serial type
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is dropped. So, the following commands executed in order will likely fail:
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<programlisting>
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CREATE TABLE <replaceable class="parameter">tablename</replaceable> (<replaceable class="parameter">colname</replaceable> SERIAL);
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@ -360,20 +375,23 @@ CREATE TABLE <replaceable class="parameter">tablename</replaceable> (<replaceabl
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</programlisting>
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The sequence will remain in the database until explicitly dropped using
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<command>DROP SEQUENCE</command>.</para>
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</caution>
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</para>
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<para>
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The <type>int8</type> type may not be available on all platforms since
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it relies on compiler support for this.
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<command>DROP SEQUENCE</command>.
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</para>
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</sect2>
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</sect1>
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<sect1>
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<title>Monetary Type</title>
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<note>
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<title>Obsolete Type</title>
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<para>
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The <type>money</type> is now obsolete. Use <type>numeric</type>
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or <type>decimal</type> instead.
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</para>
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</note>
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<para>
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The <type>money</type> type supports US-style currency with
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fixed decimal point representation.
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@ -815,13 +833,13 @@ There are several ways to affect the appearance of date/time types:
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<itemizedlist spacing="compact" mark="bullet">
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<listitem>
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<para>
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The PGDATESTYLE environment variable used by the backend directly
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The <envar>PGDATESTYLE</envar> environment variable used by the backend directly
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on postmaster startup.
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</para>
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</listitem>
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<listitem>
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<para>
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The PGDATESTYLE environment variable used by the frontend libpq
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The <envar>PGDATESTYLE</envar> environment variable used by the frontend libpq
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on session startup.
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</para>
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</listitem>
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@ -834,7 +852,7 @@ on session startup.
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</para>
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<para>
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For <productname>Postgres</productname> v6.4 (and earlier)
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For <productname>Postgres</productname> v6.5 (and earlier)
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the default date/time style is
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"non-European traditional Postgres".
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In future releases, the default may become "ISO" (compatible with ISO-8601),
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@ -901,7 +919,8 @@ on session startup.
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sets the time zone for the session.
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</para>
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</listitem>
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</itemizedlist></para>
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</itemizedlist>
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</para>
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<para>
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If an invalid time zone is specified,
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@ -1291,7 +1310,7 @@ on session startup.
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</sect2>
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<sect2>
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<title>datetime</title>
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<title><type>datetime</type></title>
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<para>
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General-use date and time is input using a wide range of
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@ -1327,7 +1346,8 @@ Timezones are either three characters (e.g. "GMT" or "PST") or ISO-compatible
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offsets to GMT (e.g. "-08" or "-08:00" when in Pacific Standard Time).
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Dates are stored internally in Greenwich Mean Time. Input and output routines
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translate time to the local time zone of the server.
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</para></sect2>
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</para>
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</sect2>
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<sect2>
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<title><type>timespan</type></title>
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@ -1364,7 +1384,7 @@ where
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</sect2>
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<sect2>
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<title>abstime</title>
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<title><type>abstime</type></title>
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<para>
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Absolute time (<type>abstime</type>) is a limited-range (+/- 68 years) and
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@ -1407,7 +1427,7 @@ allowed for "absolute time".
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</sect2>
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<sect2>
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<title>reltime</title>
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<title><type>reltime</type></title>
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<para>
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Relative time <type>reltime</type> is a limited-range (+/- 68 years)
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@ -1419,7 +1439,8 @@ relative units (months and years) and quantitative units (days, hours, etc).
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Instead, reltime
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must force months to be exactly 30 days, so time arithmetic does not
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always work as expected.
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For example, adding one reltime <literal>year</literal> to abstime <literal>today</literal> does not
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For example, adding one reltime <literal>year</literal> to
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abstime <literal>today</literal> does not
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produce today's date one year from
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now, but rather a date 360 days from today.
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</para>
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@ -1461,7 +1482,7 @@ currently mapped to the <type>timespan</type>
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</sect2>
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<sect2>
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<title>tinterval</title>
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<title><type>tinterval</type></title>
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<para>
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Time ranges are specified as:
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@ -1473,8 +1494,10 @@ where
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</programlisting>
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Special abstime values such as
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<literal>current', <literal>infinity' and <literal>-infinity' can be used.</literal></literal></literal>
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</para></sect2>
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<literal>current</literal>, <literal>infinity</literal> and
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<literal>-infinity</literal> can be used.
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</para>
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</sect2>
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</sect1>
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@ -1631,7 +1654,7 @@ where
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<title>Line Segment</title>
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<para>
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Line segments (lseg) are represented by pairs of points.
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Line segments (<type>lseg</type>) are represented by pairs of points.
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</para>
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<para>
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@ -1691,7 +1714,7 @@ are supplied to select either type in a query.
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</para>
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<para>
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path is specified using the following syntax:
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<type>path</type> is specified using the following syntax:
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<programlisting>
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( ( x1 , y1 ) , ... , ( xn , yn ) )
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@ -1704,6 +1727,7 @@ where
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a leading "[" indicates an open path
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a leading "(" indicates a closed path
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</programlisting>
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Paths are output using the first syntax.
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Note that <productname>Postgres</productname> versions prior to
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v6.1 used a format for paths which had a single leading parenthesis,
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@ -1754,7 +1778,7 @@ Circles are represented by a center point and a radius.
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</para>
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<para>
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circle is specified using the following syntax:
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<type>circle</type> is specified using the following syntax:
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<programlisting>
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< ( x , y ) , r >
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@ -1818,10 +1842,13 @@ variation in representation to represent simple host TCP/IP addresses.
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<para>
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The <type>cidr</type> type holds a CIDR network.
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The format for specifying classless networks is <replaceable class="parameter">x.x.x.x/y</replaceable>
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The format for specifying classless networks is
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<replaceable class="parameter">x.x.x.x/y</replaceable>
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where <replaceable class="parameter">x.x.x.x</replaceable> is the
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network and <replaceable class="parameter">/y</replaceable> is the number of bits in the netmask.
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If <replaceable class="parameter">/y</replaceable> omitted, it is calculated using assumptions from
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network and <replaceable class="parameter">/y</replaceable> is
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the number of bits in the netmask.
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If <replaceable class="parameter">/y</replaceable> omitted, it is
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calculated using assumptions from
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the older classfull naming system except that it is extended to include at least
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all of the octets in the input.
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</para>
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@ -1885,7 +1912,8 @@ The <type>inet</type> type is designed to hold, in one field, all of the informa
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about a host including the CIDR-style subnet that it is in.
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Note that if you want to store proper CIDR networks,
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you should use the <type>cidr</type> type.
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The <type>inet</type> type is similar to the <type>cidr</type> type except that the bits in the
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The <type>inet</type> type is similar to the <type>cidr</type>
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type except that the bits in the
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host part can be non-zero.
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Functions exist to extract the various elements of the field.
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</para>
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@ -1902,7 +1930,8 @@ On output, the <replaceable class="parameter">/y</replaceable> part is not print
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if it is <literal>/32</literal>.
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This allows the type to be used as a straight host type by just leaving off
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the bits part.
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</para></sect2>
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</para>
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</sect2>
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</sect1>
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</chapter>
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