Q: text query search and

Hi I'm trying to implement a text search in PG .

My goal to enable the user search on several columns also on partial words.

here is sample code :
create table test_test( text_data tsvector, text_a varchar,text_b varchar);

insert into test_test(text_a,text_b) select 'name 10.10.2.3 ','name3 name'
from generate_series(1,500);
update test_test set text_data=to_tsvector(text_a||' '||text_b);
CREATE INDEX test_test_idx ON test_test USING gin(text_data);

explain ANALYZE select * from test_test where text_data@
@plainto_tsquery('name');

my questions are :
1. why the index is not used (I guess it is related to the way the data is
generated)
2, how can I use pg_trgm with ts_vector to enable to answer query like
10.10 or nam ?
the idea is to use the gin index , maybe there are other option without
using pg_trgm?

thanks
amihay