<p>The lexize function is not meant to take a full string as an
argument to return lexems for. If you passed in an entire
sentence, it attempts to find that entire sentence in the
dictionary. SInce the dictionary contains only words, you will
receive an empty result set back.</p>
<pre> SELECT lexize('en_ispell', 'This is a senctece to lexize');
lexize
--------
(1 row)
If you parse a lexem from a word not in the dictionary, then you will receive an empty result. This makes sense because the word "tsearch" is not int the english dictionary. You can create your own additions to the dictionary if you like. This may be useful for scientific or technical glossaries that need to be indexed. SELECT lexize('en_ispell', 'tsearch'); lexize -------- (1 row)
</pre>
<p>This is not to say that tsearch will be ignored when adding
text information to the the tsvector index column. This will be
explained in greater detail with the table pg_ts_cfgmap.</p>
<p>Next we need to set up the configuration for mapping the
dictionay use to the lexxem parsings. This will be done by
altering the pg_ts_cfgmap table. We will insert several rows,
...
...
@@ -799,8 +822,7 @@ in the tsvector column.
configured for use within tsearch2. There are several type of
lexims we would be concerned with forcing the use of the ISpell
dictionary.</p>
<pre>
INSERT INTO pg_ts_cfgmap (ts_name, tok_alias, dict_name)
<pre> INSERT INTO pg_ts_cfgmap (ts_name, tok_alias, dict_name)
