diff options
Diffstat (limited to 'doc/src/sgml/html/textsearch-configuration.html')
| -rw-r--r-- | doc/src/sgml/html/textsearch-configuration.html | 108 |
1 files changed, 108 insertions, 0 deletions
diff --git a/doc/src/sgml/html/textsearch-configuration.html b/doc/src/sgml/html/textsearch-configuration.html new file mode 100644 index 0000000..6a530bd --- /dev/null +++ b/doc/src/sgml/html/textsearch-configuration.html @@ -0,0 +1,108 @@ +<?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>12.7. Configuration Example</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 V1.79.1" /><link rel="prev" href="textsearch-dictionaries.html" title="12.6. Dictionaries" /><link rel="next" href="textsearch-debugging.html" title="12.8. Testing and Debugging Text Search" /></head><body id="docContent" class="container-fluid col-10"><div xmlns="http://www.w3.org/TR/xhtml1/transitional" class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="5" align="center">12.7. Configuration Example</th></tr><tr><td width="10%" align="left"><a accesskey="p" href="textsearch-dictionaries.html" title="12.6. Dictionaries">Prev</a> </td><td width="10%" align="left"><a accesskey="u" href="textsearch.html" title="Chapter 12. Full Text Search">Up</a></td><th width="60%" align="center">Chapter 12. Full Text Search</th><td width="10%" align="right"><a accesskey="h" href="index.html" title="PostgreSQL 13.4 Documentation">Home</a></td><td width="10%" align="right"> <a accesskey="n" href="textsearch-debugging.html" title="12.8. Testing and Debugging Text Search">Next</a></td></tr></table><hr></hr></div><div class="sect1" id="TEXTSEARCH-CONFIGURATION"><div class="titlepage"><div><div><h2 class="title" style="clear: both">12.7. Configuration Example</h2></div></div></div><p> + A text search configuration specifies all options necessary to transform a + document into a <code class="type">tsvector</code>: the parser to use to break text + into tokens, and the dictionaries to use to transform each token into a + lexeme. Every call of + <code class="function">to_tsvector</code> or <code class="function">to_tsquery</code> + needs a text search configuration to perform its processing. + The configuration parameter + <a class="xref" href="runtime-config-client.html#GUC-DEFAULT-TEXT-SEARCH-CONFIG">default_text_search_config</a> + specifies the name of the default configuration, which is the + one used by text search functions if an explicit configuration + parameter is omitted. + It can be set in <code class="filename">postgresql.conf</code>, or set for an + individual session using the <code class="command">SET</code> command. + </p><p> + Several predefined text search configurations are available, and + you can create custom configurations easily. To facilitate management + of text search objects, a set of <acronym class="acronym">SQL</acronym> commands + is available, and there are several <span class="application">psql</span> commands that display information + about text search objects (<a class="xref" href="textsearch-psql.html" title="12.10. psql Support">Section 12.10</a>). + </p><p> + As an example we will create a configuration + <code class="literal">pg</code>, starting by duplicating the built-in + <code class="literal">english</code> configuration: + +</p><pre class="programlisting"> +CREATE TEXT SEARCH CONFIGURATION public.pg ( COPY = pg_catalog.english ); +</pre><p> + </p><p> + We will use a PostgreSQL-specific synonym list + and store it in <code class="filename">$SHAREDIR/tsearch_data/pg_dict.syn</code>. + The file contents look like: + +</p><pre class="programlisting"> +postgres pg +pgsql pg +postgresql pg +</pre><p> + + We define the synonym dictionary like this: + +</p><pre class="programlisting"> +CREATE TEXT SEARCH DICTIONARY pg_dict ( + TEMPLATE = synonym, + SYNONYMS = pg_dict +); +</pre><p> + + Next we register the <span class="productname">Ispell</span> dictionary + <code class="literal">english_ispell</code>, which has its own configuration files: + +</p><pre class="programlisting"> +CREATE TEXT SEARCH DICTIONARY english_ispell ( + TEMPLATE = ispell, + DictFile = english, + AffFile = english, + StopWords = english +); +</pre><p> + + Now we can set up the mappings for words in configuration + <code class="literal">pg</code>: + +</p><pre class="programlisting"> +ALTER TEXT SEARCH CONFIGURATION pg + ALTER MAPPING FOR asciiword, asciihword, hword_asciipart, + word, hword, hword_part + WITH pg_dict, english_ispell, english_stem; +</pre><p> + + We choose not to index or search some token types that the built-in + configuration does handle: + +</p><pre class="programlisting"> +ALTER TEXT SEARCH CONFIGURATION pg + DROP MAPPING FOR email, url, url_path, sfloat, float; +</pre><p> + </p><p> + Now we can test our configuration: + +</p><pre class="programlisting"> +SELECT * FROM ts_debug('public.pg', ' +PostgreSQL, the highly scalable, SQL compliant, open source object-relational +database management system, is now undergoing beta testing of the next +version of our software. +'); +</pre><p> + </p><p> + The next step is to set the session to use the new configuration, which was + created in the <code class="literal">public</code> schema: + +</p><pre class="screen"> +=> \dF + List of text search configurations + Schema | Name | Description +---------+------+------------- + public | pg | + +SET default_text_search_config = 'public.pg'; +SET + +SHOW default_text_search_config; + default_text_search_config +---------------------------- + public.pg +</pre><p> + </p></div><div xmlns="http://www.w3.org/TR/xhtml1/transitional" class="navfooter"><hr></hr><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="textsearch-dictionaries.html" title="12.6. Dictionaries">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="textsearch.html" title="Chapter 12. Full Text Search">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="textsearch-debugging.html" title="12.8. Testing and Debugging Text Search">Next</a></td></tr><tr><td width="40%" align="left" valign="top">12.6. Dictionaries </td><td width="20%" align="center"><a accesskey="h" href="index.html" title="PostgreSQL 13.4 Documentation">Home</a></td><td width="40%" align="right" valign="top"> 12.8. Testing and Debugging Text Search</td></tr></table></div></body></html>
\ No newline at end of file |