blob: 8bd220f77a7fb7df20b2aa8cd6807849efce6a5c (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
|
<!--
$PostgreSQL: pgsql/doc/src/sgml/ref/truncate.sgml,v 1.17 2004/03/23 13:21:41 neilc Exp $
PostgreSQL documentation
-->
<refentry id="SQL-TRUNCATE">
<refmeta>
<refentrytitle id="SQL-TRUNCATE-TITLE">TRUNCATE</refentrytitle>
<refmiscinfo>SQL - Language Statements</refmiscinfo>
</refmeta>
<refnamediv>
<refname>TRUNCATE</refname>
<refpurpose>empty a table</refpurpose>
</refnamediv>
<indexterm zone="sql-truncate">
<primary>TRUNCATE</primary>
</indexterm>
<refsynopsisdiv>
<synopsis>
TRUNCATE [ TABLE ] <replaceable class="PARAMETER">name</replaceable>
</synopsis>
</refsynopsisdiv>
<refsect1>
<title>Description</title>
<para>
<command>TRUNCATE</command> quickly removes all rows from a
table. It has the same effect as an unqualified
<command>DELETE</command> but since it does not actually scan the
table it is faster. This is most useful on large tables.
</para>
</refsect1>
<refsect1>
<title>Parameters</title>
<variablelist>
<varlistentry>
<term><replaceable class="PARAMETER">name</replaceable></term>
<listitem>
<para>
The name (optionally schema-qualified) of the table to be truncated.
</para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1>
<title>Notes</title>
<para>
<command>TRUNCATE</> cannot be used if there are foreign-key references
to the table from other tables. Checking validity in such cases would
require table scans, and the whole point is not to do one.
</para>
<para>
<command>TRUNCATE</> will not run any user-defined <literal>ON
DELETE</literal> triggers that might exist for the table.
</para>
</refsect1>
<refsect1>
<title>Examples</title>
<para>
Truncate the table <literal>bigtable</literal>:
<programlisting>
TRUNCATE TABLE bigtable;
</programlisting>
</para>
</refsect1>
<refsect1>
<title>Compatibility</title>
<para>
There is no <command>TRUNCATE</command> command in the SQL standard.
</para>
</refsect1>
</refentry>
<!-- Keep this comment at the end of the file
Local variables:
mode: sgml
sgml-omittag:t
sgml-shorttag:t
sgml-minimize-attributes:nil
sgml-always-quote-attributes:t
sgml-indent-step:1
sgml-indent-data:t
sgml-parent-document:nil
sgml-default-dtd-file:"../reference.ced"
sgml-exposed-tags:nil
sgml-local-catalogs:"/usr/lib/sgml/catalog"
sgml-local-ecat-files:nil
End:
-->
|
