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
|
<?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>F.13. dict_int — example full-text search dictionary for integers</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="contrib-dblink-build-sql-update.html" title="dblink_build_sql_update" /><link rel="next" href="dict-xsyn.html" title="F.14. dict_xsyn — example synonym full-text search dictionary" /></head><body id="docContent" class="container-fluid col-10"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="5" align="center">F.13. dict_int —
example full-text search dictionary for integers</th></tr><tr><td width="10%" align="left"><a accesskey="p" href="contrib-dblink-build-sql-update.html" title="dblink_build_sql_update">Prev</a> </td><td width="10%" align="left"><a accesskey="u" href="contrib.html" title="Appendix F. Additional Supplied Modules and Extensions">Up</a></td><th width="60%" align="center">Appendix F. Additional Supplied Modules and Extensions</th><td width="10%" align="right"><a accesskey="h" href="index.html" title="PostgreSQL 16.3 Documentation">Home</a></td><td width="10%" align="right"> <a accesskey="n" href="dict-xsyn.html" title="F.14. dict_xsyn — example synonym full-text search dictionary">Next</a></td></tr></table><hr /></div><div class="sect1" id="DICT-INT"><div class="titlepage"><div><div><h2 class="title" style="clear: both">F.13. dict_int —
example full-text search dictionary for integers <a href="#DICT-INT" class="id_link">#</a></h2></div></div></div><div class="toc"><dl class="toc"><dt><span class="sect2"><a href="dict-int.html#DICT-INT-CONFIG">F.13.1. Configuration</a></span></dt><dt><span class="sect2"><a href="dict-int.html#DICT-INT-USAGE">F.13.2. Usage</a></span></dt></dl></div><a id="id-1.11.7.23.2" class="indexterm"></a><p>
<code class="filename">dict_int</code> is an example of an add-on dictionary template
for full-text search. The motivation for this example dictionary is to
control the indexing of integers (signed and unsigned), allowing such
numbers to be indexed while preventing excessive growth in the number of
unique words, which greatly affects the performance of searching.
</p><p>
This module is considered <span class="quote">“<span class="quote">trusted</span>”</span>, that is, it can be
installed by non-superusers who have <code class="literal">CREATE</code> privilege
on the current database.
</p><div class="sect2" id="DICT-INT-CONFIG"><div class="titlepage"><div><div><h3 class="title">F.13.1. Configuration <a href="#DICT-INT-CONFIG" class="id_link">#</a></h3></div></div></div><p>
The dictionary accepts three options:
</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p>
The <code class="literal">maxlen</code> parameter specifies the maximum number of
digits allowed in an integer word. The default value is 6.
</p></li><li class="listitem"><p>
The <code class="literal">rejectlong</code> parameter specifies whether an overlength
integer should be truncated or ignored. If <code class="literal">rejectlong</code> is
<code class="literal">false</code> (the default), the dictionary returns the first
<code class="literal">maxlen</code> digits of the integer. If <code class="literal">rejectlong</code> is
<code class="literal">true</code>, the dictionary treats an overlength integer as a stop
word, so that it will not be indexed. Note that this also means that
such an integer cannot be searched for.
</p></li><li class="listitem"><p>
The <code class="literal">absval</code> parameter specifies whether leading
<span class="quote">“<span class="quote"><code class="literal">+</code></span>”</span> or <span class="quote">“<span class="quote"><code class="literal">-</code></span>”</span>
signs should be removed from integer words. The default
is <code class="literal">false</code>. When <code class="literal">true</code>, the sign is
removed before <code class="literal">maxlen</code> is applied.
</p></li></ul></div></div><div class="sect2" id="DICT-INT-USAGE"><div class="titlepage"><div><div><h3 class="title">F.13.2. Usage <a href="#DICT-INT-USAGE" class="id_link">#</a></h3></div></div></div><p>
Installing the <code class="literal">dict_int</code> extension creates a text search
template <code class="literal">intdict_template</code> and a dictionary <code class="literal">intdict</code>
based on it, with the default parameters. You can alter the
parameters, for example
</p><pre class="programlisting">
mydb# ALTER TEXT SEARCH DICTIONARY intdict (MAXLEN = 4, REJECTLONG = true);
ALTER TEXT SEARCH DICTIONARY
</pre><p>
or create new dictionaries based on the template.
</p><p>
To test the dictionary, you can try
</p><pre class="programlisting">
mydb# select ts_lexize('intdict', '12345678');
ts_lexize
-----------
{123456}
</pre><p>
but real-world usage will involve including it in a text search
configuration as described in <a class="xref" href="textsearch.html" title="Chapter 12. Full Text Search">Chapter 12</a>.
That might look like this:
</p><pre class="programlisting">
ALTER TEXT SEARCH CONFIGURATION english
ALTER MAPPING FOR int, uint WITH intdict;
</pre><p>
</p></div></div><div class="navfooter"><hr /><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="contrib-dblink-build-sql-update.html" title="dblink_build_sql_update">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="contrib.html" title="Appendix F. Additional Supplied Modules and Extensions">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="dict-xsyn.html" title="F.14. dict_xsyn — example synonym full-text search dictionary">Next</a></td></tr><tr><td width="40%" align="left" valign="top">dblink_build_sql_update </td><td width="20%" align="center"><a accesskey="h" href="index.html" title="PostgreSQL 16.3 Documentation">Home</a></td><td width="40%" align="right" valign="top"> F.14. dict_xsyn — example synonym full-text search dictionary</td></tr></table></div></body></html>
|
