Query Rewrite Template in Oracle SQL - sql

Question

I have a Oracle SQL Query as below :
select id from docs where CONTAINS (text,
'<query>
<textquery lang="ENGLISH" grammar="CONTEXT"> Informix
<progression>
<seq><rewrite>transform((TOKENS, "{", "}", "AND"))</rewrite></seq>
</progression>
</textquery>
</query>')>0;
The Query Works as expected. But I want to search for word Inform / Infor / Info. So I altered the query to below :
select id from docs where CONTAINS (text,
'<query>
<textquery lang="ENGLISH" grammar="CONTEXT"> Informix
<progression>
<seq><rewrite>transform((TOKENS, "?{", "}", "AND"))</rewrite></seq>
</progression>
</textquery>
</query>')>0;
By adding extra "?" in transform function. But this looks for informix / informi / inform / infor / info / inf / in. I want to restrict the search to a specific characters 4. Say till info. How can the same be achieved?
Thanks.

Answer 1

To find all documents that contain at least one occurrence of any of the terms between informix and info use the OR operator
and list all you allowerd terms in the template
<query>
<textquery lang="ENGLISH" grammar="CONTEXT"> informix informi inform infor info
<progression>
<seq><rewrite>transform((TOKENS, "{", "}", "OR"))</rewrite></seq>
</progression>
</textquery>
</query>
But the usage of template is not realy meaninfull here.
The same result you get with a direct query
select score(1), id from docs
where contains(text,'informix OR informi OR inform OR infor OR info',1) > 0
order by 1 desc;
The advantage of this case is that you can controll the score by prefering the documents with longer string with higher weights
select score(1), id from docs
where contains(text,'informix*5 OR informi*4 OR inform*3 OR infor*2 OR info',1) > 0
order by 1 desc;
Btw the ? (fuzzy) operator is used IMO to find misspelled words, not the exact prefixes of a term.
UPDATE
The concatenation of the prefixes you may assembly in PL/SQL or if necessary in SQL such as follows:
with txt as (
select 'informix' text from dual),
txt2 as (
select
substr(text,1,length(text) -rownum+1) text
from txt connect by level <= length(text) -3
)
select
LISTAGG( text, ', ') WITHIN GROUP (ORDER BY text desc)
from txt2
.
informix, informi, inform, infor, info