> Indexing the t_name.name field, I can increase speed, but only if I
> restrict my search to something like :
>
> select *
> from t_name
> where t_name.name like 'my_search%'
>
> (In this case it takes generally less than 1 second)
>
>
> My question : Are there algorithms or tools that can speed up such a
> type of queries ("like" condition begining with a "%" symbol) ?
Apart from indexing the field you could use full text indexing. See
http://techdocs.postgresql.org/techdocs/fulltextindexing.php
What other types of queries are you running that you want to speed up ?