&pg-tsparser;

<!ENTITY pg-tsparser SYSTEM "pg_tsparser.sgml">

<sect1 id="pg-tsparser">

<title>pg_tsparser</title>

<para>

The <filename>pg_tsparser</filename> is a Postgres Pro extension that

modifies the default text search parser. In addition to the default

search results, this extension also returns a single word in the

following cases:

</para>

<itemizedlist spacing="compact">

<listitem>

<para>

words that include underscores

</para>

</listitem>

<listitem>

<para>

words that include numbers and letters separated by the hyphen

character

</para>

</listitem>

</itemizedlist>

<sect2 id="pg-tsparser-install">

<title>Installation and Setup</title>

<para>

The <filename>pg_tsparser</filename> extension is included into the

Postgres Pro. To enable <filename>pg_tsparser</filename>,

create the <filename>pg_tsparser</filename> extension for each

database you are planning to use:

</para>

<programlisting>

CREATE EXTENSION pg_tsparser;

</programlisting>

<para>

Once <filename>pg_tsparser</filename> is enabled, you can create

your own text search configuration. For example:

</para>

<programlisting>

CREATE TEXT SEARCH CONFIGURATION english_ts (

PARSER = tsparser

);

COMMENT ON TEXT SEARCH CONFIGURATION english_ts IS 'text search configuration for english language';

ALTER TEXT SEARCH CONFIGURATION english_ts

ADD MAPPING FOR email, file, float, host, hword_numpart, int,

numhword, numword, sfloat, uint, url, url_path, version

WITH simple;

ALTER TEXT SEARCH CONFIGURATION english_ts

ADD MAPPING FOR asciiword, asciihword, hword_asciipart,

word, hword, hword_part

WITH english_stem;

</programlisting>

</sect2>

<sect2 id="pg-tsparser-examples">

<title>Examples</title>

<para>

The following examples illustrate the difference in search results

returned by <filename>pg_tsparser</filename> and the default parser:

</para>

<programlisting>

SELECT to_tsvector('english', 'pg_trgm') as def_parser,

to_tsvector('english_ts', 'pg_trgm') as new_parser;

def_parser | new_parser

-----------------+-----------------------------

'pg':1 'trgm':2 | 'pg':2 'pg_trgm':1 'trgm':3

(1 row)

SELECT to_tsvector('english', '123-abc') as def_parser,

to_tsvector('english_ts', '123-abc') as new_parser;

def_parser | new_parser

-----------------+-----------------------------

'123':1 'abc':2 | '123':2 '123-abc':1 'abc':3

(1 row)

SELECT to_tsvector('english', 'rel-3.2-A') as def_parser,

to_tsvector('english_ts', 'rel-3.2-A') as new_parser;

def_parser | new_parser

------------------+-------------------------------

'-3.2':2 'rel':1 | '3.2':3 'rel':2 'rel-3.2-a':1

(1 row)

</programlisting>

</sect2>

<sect2 id="pg-tsparser-authors">

<title>Authors</title>

<para>

Postgres Professional, Moscow, Russia

</para>

</sect2>

</sect1>