R: [GENERAL] Special index for "like"-based query

>>And, basically, if you need help with some queries you could try
>>posting them whole, even redacted, along the table defs, this way
>>perople can see the problem and not invent one based on a partial
>>description

Thank you very much, very kind from you.

The index applied on the timestamp field is a btree("timestamp")

The query is:

select domain, sum(accessi) as c_count from TABLE where action='1' AND profile IN ('PROFILE_CODE') AND timestamp::date
BETWEEN'2016-12-27' AND '2016-12-30' AND timestamp::time BETWEEN '00:00:00' AND '23:59:59' GROUP BY domain ORDER BY
c_countDESC  LIMIT 101 

The table format is:
  Column   |           Type           |                                   Modifiers
-----------+--------------------------+--------------------------------------------------------------------------------
 id        | numeric(1000,1)          | not null default function_get_next_sequence('webtraffic_archive_id_seq'::text)
 timestamp | timestamp with time zone |
 domain    | character varying(255)   |
 action    | character varying(5)     |
 profile   | character varying        |
 accessi   | bigint                   |
 url       | text                     |

Indexes:
    "webtraffic_archive_day_2016_04_15_action_wbidx" btree (action)
    "webtraffic_archive_day_2016_04_15_domain_wbidx" btree (domain)
    "webtraffic_archive_day_2016_04_15_profile_wbidx" btree (profile) CLUSTER
    "webtraffic_archive_day_2016_04_15_timestamp_wbidx" btree ("timestamp")

Last question: the table is partitioned. I need to manually create index for every sub-tables or there is a way to
createon every sub-tables once? 

THANK YOU!
/F