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<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml"><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /><title>8.1. Numeric Types</title><link rel="stylesheet" type="text/css" href="stylesheet.css" /><link rev="made" href="pgsql-docs@lists.postgresql.org" /><meta name="generator" content="DocBook XSL Stylesheets Vsnapshot" /><link rel="prev" href="datatype.html" title="Chapter 8. Data Types" /><link rel="next" href="datatype-money.html" title="8.2. Monetary Types" /></head><body id="docContent" class="container-fluid col-10"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="5" align="center">8.1. Numeric Types</th></tr><tr><td width="10%" align="left"><a accesskey="p" href="datatype.html" title="Chapter 8. Data Types">Prev</a> </td><td width="10%" align="left"><a accesskey="u" href="datatype.html" title="Chapter 8. Data Types">Up</a></td><th width="60%" align="center">Chapter 8. Data Types</th><td width="10%" align="right"><a accesskey="h" href="index.html" title="PostgreSQL 15.7 Documentation">Home</a></td><td width="10%" align="right"> <a accesskey="n" href="datatype-money.html" title="8.2. Monetary Types">Next</a></td></tr></table><hr /></div><div class="sect1" id="DATATYPE-NUMERIC"><div class="titlepage"><div><div><h2 class="title" style="clear: both">8.1. Numeric Types</h2></div></div></div><div class="toc"><dl class="toc"><dt><span class="sect2"><a href="datatype-numeric.html#DATATYPE-INT">8.1.1. Integer Types</a></span></dt><dt><span class="sect2"><a href="datatype-numeric.html#DATATYPE-NUMERIC-DECIMAL">8.1.2. Arbitrary Precision Numbers</a></span></dt><dt><span class="sect2"><a href="datatype-numeric.html#DATATYPE-FLOAT">8.1.3. Floating-Point Types</a></span></dt><dt><span class="sect2"><a href="datatype-numeric.html#DATATYPE-SERIAL">8.1.4. Serial Types</a></span></dt></dl></div><a id="id-1.5.7.9.2" class="indexterm"></a><p>
Numeric types consist of two-, four-, and eight-byte integers,
four- and eight-byte floating-point numbers, and selectable-precision
decimals. <a class="xref" href="datatype-numeric.html#DATATYPE-NUMERIC-TABLE" title="Table 8.2. Numeric Types">Table 8.2</a> lists the
available types.
</p><div class="table" id="DATATYPE-NUMERIC-TABLE"><p class="title"><strong>Table 8.2. Numeric Types</strong></p><div class="table-contents"><table class="table" summary="Numeric Types" border="1"><colgroup><col class="col1" /><col class="col2" /><col class="col3" /><col class="col4" /></colgroup><thead><tr><th>Name</th><th>Storage Size</th><th>Description</th><th>Range</th></tr></thead><tbody><tr><td><code class="type">smallint</code></td><td>2 bytes</td><td>small-range integer</td><td>-32768 to +32767</td></tr><tr><td><code class="type">integer</code></td><td>4 bytes</td><td>typical choice for integer</td><td>-2147483648 to +2147483647</td></tr><tr><td><code class="type">bigint</code></td><td>8 bytes</td><td>large-range integer</td><td>-9223372036854775808 to +9223372036854775807</td></tr><tr><td><code class="type">decimal</code></td><td>variable</td><td>user-specified precision, exact</td><td>up to 131072 digits before the decimal point; up to 16383 digits after the decimal point</td></tr><tr><td><code class="type">numeric</code></td><td>variable</td><td>user-specified precision, exact</td><td>up to 131072 digits before the decimal point; up to 16383 digits after the decimal point</td></tr><tr><td><code class="type">real</code></td><td>4 bytes</td><td>variable-precision, inexact</td><td>6 decimal digits precision</td></tr><tr><td><code class="type">double precision</code></td><td>8 bytes</td><td>variable-precision, inexact</td><td>15 decimal digits precision</td></tr><tr><td><code class="type">smallserial</code></td><td>2 bytes</td><td>small autoincrementing integer</td><td>1 to 32767</td></tr><tr><td><code class="type">serial</code></td><td>4 bytes</td><td>autoincrementing integer</td><td>1 to 2147483647</td></tr><tr><td><code class="type">bigserial</code></td><td>8 bytes</td><td>large autoincrementing integer</td><td>1 to 9223372036854775807</td></tr></tbody></table></div></div><br class="table-break" /><p>
The syntax of constants for the numeric types is described in
<a class="xref" href="sql-syntax-lexical.html#SQL-SYNTAX-CONSTANTS" title="4.1.2. Constants">Section 4.1.2</a>. The numeric types have a
full set of corresponding arithmetic operators and
functions. Refer to <a class="xref" href="functions.html" title="Chapter 9. Functions and Operators">Chapter 9</a> for more
information. The following sections describe the types in detail.
</p><div class="sect2" id="DATATYPE-INT"><div class="titlepage"><div><div><h3 class="title">8.1.1. Integer Types</h3></div></div></div><a id="id-1.5.7.9.6.2" class="indexterm"></a><a id="id-1.5.7.9.6.3" class="indexterm"></a><a id="id-1.5.7.9.6.4" class="indexterm"></a><a id="id-1.5.7.9.6.5" class="indexterm"></a><a id="id-1.5.7.9.6.6" class="indexterm"></a><a id="id-1.5.7.9.6.7" class="indexterm"></a><p>
The types <code class="type">smallint</code>, <code class="type">integer</code>, and
<code class="type">bigint</code> store whole numbers, that is, numbers without
fractional components, of various ranges. Attempts to store
values outside of the allowed range will result in an error.
</p><p>
The type <code class="type">integer</code> is the common choice, as it offers
the best balance between range, storage size, and performance.
The <code class="type">smallint</code> type is generally only used if disk
space is at a premium. The <code class="type">bigint</code> type is designed to be
used when the range of the <code class="type">integer</code> type is insufficient.
</p><p>
<acronym class="acronym">SQL</acronym> only specifies the integer types
<code class="type">integer</code> (or <code class="type">int</code>),
<code class="type">smallint</code>, and <code class="type">bigint</code>. The
type names <code class="type">int2</code>, <code class="type">int4</code>, and
<code class="type">int8</code> are extensions, which are also used by some
other <acronym class="acronym">SQL</acronym> database systems.
</p></div><div class="sect2" id="DATATYPE-NUMERIC-DECIMAL"><div class="titlepage"><div><div><h3 class="title">8.1.2. Arbitrary Precision Numbers</h3></div></div></div><a id="id-1.5.7.9.7.2" class="indexterm"></a><a id="id-1.5.7.9.7.3" class="indexterm"></a><a id="id-1.5.7.9.7.4" class="indexterm"></a><p>
The type <code class="type">numeric</code> can store numbers with a
very large number of digits. It is especially recommended for
storing monetary amounts and other quantities where exactness is
required. Calculations with <code class="type">numeric</code> values yield exact
results where possible, e.g., addition, subtraction, multiplication.
However, calculations on <code class="type">numeric</code> values are very slow
compared to the integer types, or to the floating-point types
described in the next section.
</p><p>
We use the following terms below: The
<em class="firstterm">precision</em> of a <code class="type">numeric</code>
is the total count of significant digits in the whole number,
that is, the number of digits to both sides of the decimal point.
The <em class="firstterm">scale</em> of a <code class="type">numeric</code> is the
count of decimal digits in the fractional part, to the right of the
decimal point. So the number 23.5141 has a precision of 6 and a
scale of 4. Integers can be considered to have a scale of zero.
</p><p>
Both the maximum precision and the maximum scale of a
<code class="type">numeric</code> column can be
configured. To declare a column of type <code class="type">numeric</code> use
the syntax:
</p><pre class="programlisting">
NUMERIC(<em class="replaceable"><code>precision</code></em>, <em class="replaceable"><code>scale</code></em>)
</pre><p>
The precision must be positive, while the scale may be positive or
negative (see below). Alternatively:
</p><pre class="programlisting">
NUMERIC(<em class="replaceable"><code>precision</code></em>)
</pre><p>
selects a scale of 0. Specifying:
</p><pre class="programlisting">
NUMERIC
</pre><p>
without any precision or scale creates an <span class="quote">“<span class="quote">unconstrained
numeric</span>”</span> column in which numeric values of any length can be
stored, up to the implementation limits. A column of this kind will
not coerce input values to any particular scale, whereas
<code class="type">numeric</code> columns with a declared scale will coerce
input values to that scale. (The <acronym class="acronym">SQL</acronym> standard
requires a default scale of 0, i.e., coercion to integer
precision. We find this a bit useless. If you're concerned
about portability, always specify the precision and scale
explicitly.)
</p><div class="note"><h3 class="title">Note</h3><p>
The maximum precision that can be explicitly specified in
a <code class="type">numeric</code> type declaration is 1000. An
unconstrained <code class="type">numeric</code> column is subject to the limits
described in <a class="xref" href="datatype-numeric.html#DATATYPE-NUMERIC-TABLE" title="Table 8.2. Numeric Types">Table 8.2</a>.
</p></div><p>
If the scale of a value to be stored is greater than the declared
scale of the column, the system will round the value to the specified
number of fractional digits. Then, if the number of digits to the
left of the decimal point exceeds the declared precision minus the
declared scale, an error is raised.
For example, a column declared as
</p><pre class="programlisting">
NUMERIC(3, 1)
</pre><p>
will round values to 1 decimal place and can store values between
-99.9 and 99.9, inclusive.
</p><p>
Beginning in <span class="productname">PostgreSQL</span> 15, it is allowed
to declare a <code class="type">numeric</code> column with a negative scale. Then
values will be rounded to the left of the decimal point. The
precision still represents the maximum number of non-rounded digits.
Thus, a column declared as
</p><pre class="programlisting">
NUMERIC(2, -3)
</pre><p>
will round values to the nearest thousand and can store values
between -99000 and 99000, inclusive.
It is also allowed to declare a scale larger than the declared
precision. Such a column can only hold fractional values, and it
requires the number of zero digits just to the right of the decimal
point to be at least the declared scale minus the declared precision.
For example, a column declared as
</p><pre class="programlisting">
NUMERIC(3, 5)
</pre><p>
will round values to 5 decimal places and can store values between
-0.00999 and 0.00999, inclusive.
</p><div class="note"><h3 class="title">Note</h3><p>
<span class="productname">PostgreSQL</span> permits the scale in a
<code class="type">numeric</code> type declaration to be any value in the range
-1000 to 1000. However, the <acronym class="acronym">SQL</acronym> standard requires
the scale to be in the range 0 to <em class="replaceable"><code>precision</code></em>.
Using scales outside that range may not be portable to other database
systems.
</p></div><p>
Numeric values are physically stored without any extra leading or
trailing zeroes. Thus, the declared precision and scale of a column
are maximums, not fixed allocations. (In this sense the <code class="type">numeric</code>
type is more akin to <code class="type">varchar(<em class="replaceable"><code>n</code></em>)</code>
than to <code class="type">char(<em class="replaceable"><code>n</code></em>)</code>.) The actual storage
requirement is two bytes for each group of four decimal digits,
plus three to eight bytes overhead.
</p><a id="id-1.5.7.9.7.13" class="indexterm"></a><a id="id-1.5.7.9.7.14" class="indexterm"></a><a id="id-1.5.7.9.7.15" class="indexterm"></a><p>
In addition to ordinary numeric values, the <code class="type">numeric</code> type
has several special values:
</p><div class="literallayout"><p><br />
<code class="literal">Infinity</code><br />
<code class="literal">-Infinity</code><br />
<code class="literal">NaN</code><br />
</p></div><p>
These are adapted from the IEEE 754 standard, and represent
<span class="quote">“<span class="quote">infinity</span>”</span>, <span class="quote">“<span class="quote">negative infinity</span>”</span>, and
<span class="quote">“<span class="quote">not-a-number</span>”</span>, respectively. When writing these values
as constants in an SQL command, you must put quotes around them,
for example <code class="literal">UPDATE table SET x = '-Infinity'</code>.
On input, these strings are recognized in a case-insensitive manner.
The infinity values can alternatively be spelled <code class="literal">inf</code>
and <code class="literal">-inf</code>.
</p><p>
The infinity values behave as per mathematical expectations. For
example, <code class="literal">Infinity</code> plus any finite value equals
<code class="literal">Infinity</code>, as does <code class="literal">Infinity</code>
plus <code class="literal">Infinity</code>; but <code class="literal">Infinity</code>
minus <code class="literal">Infinity</code> yields <code class="literal">NaN</code> (not a
number), because it has no well-defined interpretation. Note that an
infinity can only be stored in an unconstrained <code class="type">numeric</code>
column, because it notionally exceeds any finite precision limit.
</p><p>
The <code class="literal">NaN</code> (not a number) value is used to represent
undefined calculational results. In general, any operation with
a <code class="literal">NaN</code> input yields another <code class="literal">NaN</code>.
The only exception is when the operation's other inputs are such that
the same output would be obtained if the <code class="literal">NaN</code> were to
be replaced by any finite or infinite numeric value; then, that output
value is used for <code class="literal">NaN</code> too. (An example of this
principle is that <code class="literal">NaN</code> raised to the zero power
yields one.)
</p><div class="note"><h3 class="title">Note</h3><p>
In most implementations of the <span class="quote">“<span class="quote">not-a-number</span>”</span> concept,
<code class="literal">NaN</code> is not considered equal to any other numeric
value (including <code class="literal">NaN</code>). In order to allow
<code class="type">numeric</code> values to be sorted and used in tree-based
indexes, <span class="productname">PostgreSQL</span> treats <code class="literal">NaN</code>
values as equal, and greater than all non-<code class="literal">NaN</code>
values.
</p></div><p>
The types <code class="type">decimal</code> and <code class="type">numeric</code> are
equivalent. Both types are part of the <acronym class="acronym">SQL</acronym>
standard.
</p><p>
When rounding values, the <code class="type">numeric</code> type rounds ties away
from zero, while (on most machines) the <code class="type">real</code>
and <code class="type">double precision</code> types round ties to the nearest even
number. For example:
</p><pre class="programlisting">
SELECT x,
round(x::numeric) AS num_round,
round(x::double precision) AS dbl_round
FROM generate_series(-3.5, 3.5, 1) as x;
x | num_round | dbl_round
------+-----------+-----------
-3.5 | -4 | -4
-2.5 | -3 | -2
-1.5 | -2 | -2
-0.5 | -1 | -0
0.5 | 1 | 0
1.5 | 2 | 2
2.5 | 3 | 2
3.5 | 4 | 4
(8 rows)
</pre><p>
</p></div><div class="sect2" id="DATATYPE-FLOAT"><div class="titlepage"><div><div><h3 class="title">8.1.3. Floating-Point Types</h3></div></div></div><a id="id-1.5.7.9.8.2" class="indexterm"></a><a id="id-1.5.7.9.8.3" class="indexterm"></a><a id="id-1.5.7.9.8.4" class="indexterm"></a><a id="id-1.5.7.9.8.5" class="indexterm"></a><a id="id-1.5.7.9.8.6" class="indexterm"></a><p>
The data types <code class="type">real</code> and <code class="type">double precision</code> are
inexact, variable-precision numeric types. On all currently supported
platforms, these types are implementations of <acronym class="acronym">IEEE</acronym>
Standard 754 for Binary Floating-Point Arithmetic (single and double
precision, respectively), to the extent that the underlying processor,
operating system, and compiler support it.
</p><p>
Inexact means that some values cannot be converted exactly to the
internal format and are stored as approximations, so that storing
and retrieving a value might show slight discrepancies.
Managing these errors and how they propagate through calculations
is the subject of an entire branch of mathematics and computer
science and will not be discussed here, except for the
following points:
</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p>
If you require exact storage and calculations (such as for
monetary amounts), use the <code class="type">numeric</code> type instead.
</p></li><li class="listitem"><p>
If you want to do complicated calculations with these types
for anything important, especially if you rely on certain
behavior in boundary cases (infinity, underflow), you should
evaluate the implementation carefully.
</p></li><li class="listitem"><p>
Comparing two floating-point values for equality might not
always work as expected.
</p></li></ul></div><p>
</p><p>
On all currently supported platforms, the <code class="type">real</code> type has a
range of around 1E-37 to 1E+37 with a precision of at least 6 decimal
digits. The <code class="type">double precision</code> type has a range of around
1E-307 to 1E+308 with a precision of at least 15 digits. Values that are
too large or too small will cause an error. Rounding might take place if
the precision of an input number is too high. Numbers too close to zero
that are not representable as distinct from zero will cause an underflow
error.
</p><p>
By default, floating point values are output in text form in their
shortest precise decimal representation; the decimal value produced is
closer to the true stored binary value than to any other value
representable in the same binary precision. (However, the output value is
currently never <span class="emphasis"><em>exactly</em></span> midway between two
representable values, in order to avoid a widespread bug where input
routines do not properly respect the round-to-nearest-even rule.) This value will
use at most 17 significant decimal digits for <code class="type">float8</code>
values, and at most 9 digits for <code class="type">float4</code> values.
</p><div class="note"><h3 class="title">Note</h3><p>
This shortest-precise output format is much faster to generate than the
historical rounded format.
</p></div><p>
For compatibility with output generated by older versions
of <span class="productname">PostgreSQL</span>, and to allow the output
precision to be reduced, the <a class="xref" href="runtime-config-client.html#GUC-EXTRA-FLOAT-DIGITS">extra_float_digits</a>
parameter can be used to select rounded decimal output instead. Setting a
value of 0 restores the previous default of rounding the value to 6
(for <code class="type">float4</code>) or 15 (for <code class="type">float8</code>)
significant decimal digits. Setting a negative value reduces the number
of digits further; for example -2 would round output to 4 or 13 digits
respectively.
</p><p>
Any value of <a class="xref" href="runtime-config-client.html#GUC-EXTRA-FLOAT-DIGITS">extra_float_digits</a> greater than 0
selects the shortest-precise format.
</p><div class="note"><h3 class="title">Note</h3><p>
Applications that wanted precise values have historically had to set
<a class="xref" href="runtime-config-client.html#GUC-EXTRA-FLOAT-DIGITS">extra_float_digits</a> to 3 to obtain them. For
maximum compatibility between versions, they should continue to do so.
</p></div><a id="id-1.5.7.9.8.15" class="indexterm"></a><a id="id-1.5.7.9.8.16" class="indexterm"></a><p>
In addition to ordinary numeric values, the floating-point types
have several special values:
</p><div class="literallayout"><p><br />
<code class="literal">Infinity</code><br />
<code class="literal">-Infinity</code><br />
<code class="literal">NaN</code><br />
</p></div><p>
These represent the IEEE 754 special values
<span class="quote">“<span class="quote">infinity</span>”</span>, <span class="quote">“<span class="quote">negative infinity</span>”</span>, and
<span class="quote">“<span class="quote">not-a-number</span>”</span>, respectively. When writing these values
as constants in an SQL command, you must put quotes around them,
for example <code class="literal">UPDATE table SET x = '-Infinity'</code>. On input,
these strings are recognized in a case-insensitive manner.
The infinity values can alternatively be spelled <code class="literal">inf</code>
and <code class="literal">-inf</code>.
</p><div class="note"><h3 class="title">Note</h3><p>
IEEE 754 specifies that <code class="literal">NaN</code> should not compare equal
to any other floating-point value (including <code class="literal">NaN</code>).
In order to allow floating-point values to be sorted and used
in tree-based indexes, <span class="productname">PostgreSQL</span> treats
<code class="literal">NaN</code> values as equal, and greater than all
non-<code class="literal">NaN</code> values.
</p></div><p>
<span class="productname">PostgreSQL</span> also supports the SQL-standard
notations <code class="type">float</code> and
<code class="type">float(<em class="replaceable"><code>p</code></em>)</code> for specifying
inexact numeric types. Here, <em class="replaceable"><code>p</code></em> specifies
the minimum acceptable precision in <span class="emphasis"><em>binary</em></span> digits.
<span class="productname">PostgreSQL</span> accepts
<code class="type">float(1)</code> to <code class="type">float(24)</code> as selecting the
<code class="type">real</code> type, while
<code class="type">float(25)</code> to <code class="type">float(53)</code> select
<code class="type">double precision</code>. Values of <em class="replaceable"><code>p</code></em>
outside the allowed range draw an error.
<code class="type">float</code> with no precision specified is taken to mean
<code class="type">double precision</code>.
</p></div><div class="sect2" id="DATATYPE-SERIAL"><div class="titlepage"><div><div><h3 class="title">8.1.4. Serial Types</h3></div></div></div><a id="id-1.5.7.9.9.2" class="indexterm"></a><a id="id-1.5.7.9.9.3" class="indexterm"></a><a id="id-1.5.7.9.9.4" class="indexterm"></a><a id="id-1.5.7.9.9.5" class="indexterm"></a><a id="id-1.5.7.9.9.6" class="indexterm"></a><a id="id-1.5.7.9.9.7" class="indexterm"></a><a id="id-1.5.7.9.9.8" class="indexterm"></a><a id="id-1.5.7.9.9.9" class="indexterm"></a><div class="note"><h3 class="title">Note</h3><p>
This section describes a PostgreSQL-specific way to create an
autoincrementing column. Another way is to use the SQL-standard
identity column feature, described at <a class="xref" href="sql-createtable.html" title="CREATE TABLE"><span class="refentrytitle">CREATE TABLE</span></a>.
</p></div><p>
The data types <code class="type">smallserial</code>, <code class="type">serial</code> and
<code class="type">bigserial</code> are not true types, but merely
a notational convenience for creating unique identifier columns
(similar to the <code class="literal">AUTO_INCREMENT</code> property
supported by some other databases). In the current
implementation, specifying:
</p><pre class="programlisting">
CREATE TABLE <em class="replaceable"><code>tablename</code></em> (
<em class="replaceable"><code>colname</code></em> SERIAL
);
</pre><p>
is equivalent to specifying:
</p><pre class="programlisting">
CREATE SEQUENCE <em class="replaceable"><code>tablename</code></em>_<em class="replaceable"><code>colname</code></em>_seq AS integer;
CREATE TABLE <em class="replaceable"><code>tablename</code></em> (
<em class="replaceable"><code>colname</code></em> integer NOT NULL DEFAULT nextval('<em class="replaceable"><code>tablename</code></em>_<em class="replaceable"><code>colname</code></em>_seq')
);
ALTER SEQUENCE <em class="replaceable"><code>tablename</code></em>_<em class="replaceable"><code>colname</code></em>_seq OWNED BY <em class="replaceable"><code>tablename</code></em>.<em class="replaceable"><code>colname</code></em>;
</pre><p>
Thus, we have created an integer column and arranged for its default
values to be assigned from a sequence generator. A <code class="literal">NOT NULL</code>
constraint is applied to ensure that a null value cannot be
inserted. (In most cases you would also want to attach a
<code class="literal">UNIQUE</code> or <code class="literal">PRIMARY KEY</code> constraint to prevent
duplicate values from being inserted by accident, but this is
not automatic.) Lastly, the sequence is marked as <span class="quote">“<span class="quote">owned by</span>”</span>
the column, so that it will be dropped if the column or table is dropped.
</p><div class="note"><h3 class="title">Note</h3><p>
Because <code class="type">smallserial</code>, <code class="type">serial</code> and
<code class="type">bigserial</code> are implemented using sequences, there may
be "holes" or gaps in the sequence of values which appears in the
column, even if no rows are ever deleted. A value allocated
from the sequence is still "used up" even if a row containing that
value is never successfully inserted into the table column. This
may happen, for example, if the inserting transaction rolls back.
See <code class="literal">nextval()</code> in <a class="xref" href="functions-sequence.html" title="9.17. Sequence Manipulation Functions">Section 9.17</a>
for details.
</p></div><p>
To insert the next value of the sequence into the <code class="type">serial</code>
column, specify that the <code class="type">serial</code>
column should be assigned its default value. This can be done
either by excluding the column from the list of columns in
the <code class="command">INSERT</code> statement, or through the use of
the <code class="literal">DEFAULT</code> key word.
</p><p>
The type names <code class="type">serial</code> and <code class="type">serial4</code> are
equivalent: both create <code class="type">integer</code> columns. The type
names <code class="type">bigserial</code> and <code class="type">serial8</code> work
the same way, except that they create a <code class="type">bigint</code>
column. <code class="type">bigserial</code> should be used if you anticipate
the use of more than 2<sup>31</sup> identifiers over the
lifetime of the table. The type names <code class="type">smallserial</code> and
<code class="type">serial2</code> also work the same way, except that they
create a <code class="type">smallint</code> column.
</p><p>
The sequence created for a <code class="type">serial</code> column is
automatically dropped when the owning column is dropped.
You can drop the sequence without dropping the column, but this
will force removal of the column default expression.
</p></div></div><div class="navfooter"><hr /><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="datatype.html" title="Chapter 8. Data Types">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="datatype.html" title="Chapter 8. Data Types">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="datatype-money.html" title="8.2. Monetary Types">Next</a></td></tr><tr><td width="40%" align="left" valign="top">Chapter 8. Data Types </td><td width="20%" align="center"><a accesskey="h" href="index.html" title="PostgreSQL 15.7 Documentation">Home</a></td><td width="40%" align="right" valign="top"> 8.2. Monetary Types</td></tr></table></div></body></html>
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