create table MAIN_T
(
 ID        NUMBER    NOT NULL,
 DATE_ID   DATE NOT NULL,
 DATE1_ID DATE)
PARTITION BY RANGE (DATE_ID)
INTERVAL(numtodsinterval(1,'DAY'))
(PARTITION VALUES LESS THAN (TO_DATE('2012-12-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS')))
PARALLEL 8; 

declare 
 v$date date;
begin
for i in 1..20000
loop
   v$date := trunc(SYSDATE) + round(i/1000);
  insert into MAIN_T(ID,DATE_ID, DATE1_ID)
  values(i,v$date,trunc(SYSDATE)-90+i);
end loop;  
commit;
end;

alter table MAIN_T add constraint MAIN_PK primary key(ID);


create table D_TIME
(
  day_id DATE not null,
  my_test varchar2(10));
alter table D_TIME  add constraint DTI_PK primary key(DAY_ID);

insert into D_TIME(day_id)
select DATE_ID
from MAIN_T
UNION
select DATE1_ID
from MAIN_T;
commit;

alter table MAIN_T   add constraint MAIN_FK foreign key (DATE_ID)  references D_TIME(DAY_ID);


begin
 dbms_stats.gather_table_stats(ownname => '*****',tabname => 'MAIN_T',method_opt => 'FOR ALL COLUMNS SIZE 254');
 dbms_stats.gather_index_stats(ownname => '*****',indname => 'MAIN_PK');
 dbms_stats.gather_table_stats(ownname => '*****',tabname => 'D_TIME',method_opt => 'FOR ALL COLUMNS SIZE 254');
 dbms_stats.gather_index_stats(ownname => '*****',indname => 'DTI_PK'); 
end;

explain plan for
select A.*, B.day_id
from provar.MAIN_T A
inner join provar.D_TIME B on A.DATE_ID=B.day_id
where A.DATE_ID between trunc(SYSDATE) and trunc(SYSDATE)+10;
select *
from table(dbms_xplan.display); 

Plan hash value: 3214451937
 
----------------------------------------------------------------------------------------------------
| Id  | Operation                 | Name   | Rows  | Bytes | Cost (%CPU)| Time     | Pstart| Pstop |
----------------------------------------------------------------------------------------------------
|   0 | SELECT STATEMENT          |        | 10500 |   205K|  5090   (1)| 00:00:01 |       |       |
|*  1 |  FILTER                   |        |       |       |            |          |       |       |
|   2 |   PARTITION RANGE ITERATOR|        | 10500 |   205K|  5090   (1)| 00:00:01 |   KEY |   KEY |
|*  3 |    TABLE ACCESS FULL      | MAIN_T | 10500 |   205K|  5090   (1)| 00:00:01 |   KEY |   KEY |
----------------------------------------------------------------------------------------------------
 
Predicate Information (identified by operation id):
---------------------------------------------------
 
   1 - filter(TRUNC(SYSDATE@!)+10>=TRUNC(SYSDATE@!))
   3 - filter("A"."DATE_ID"<=TRUNC(SYSDATE@!)+10 AND "A"."DATE_ID">=TRUNC(SYSDATE@!))
 
Note
-----
   - automatic DOP: Computed Degree of Parallelism is 1 because of parallel threshold

explain plan for
select A.*, B.day_id, B.my_test
from provar.MAIN_T A
inner join provar.D_TIME B on A.DATE_ID=B.day_id
where A.DATE_ID between trunc(SYSDATE) and trunc(SYSDATE)+10;
select *
from table(dbms_xplan.display); 

Plan hash value: 1795835293
 
----------------------------------------------------------------------------------------------------------------
| Id  | Operation                             | Name   | Rows  | Bytes | Cost (%CPU)| Time     | Pstart| Pstop |
----------------------------------------------------------------------------------------------------------------
|   0 | SELECT STATEMENT                      |        |  5000 |   136K|  2315   (1)| 00:00:01 |       |       |
|*  1 |  FILTER                               |        |       |       |            |          |       |       |
|   2 |   NESTED LOOPS                        |        |  5000 |   136K|  2315   (1)| 00:00:01 |       |       |
|   3 |    TABLE ACCESS BY INDEX ROWID BATCHED| D_TIME |    10 |    80 |     3   (0)| 00:00:01 |       |       |
|*  4 |     INDEX RANGE SCAN                  | DTI_PK |    10 |       |     2   (0)| 00:00:01 |       |       |
|   5 |    PARTITION RANGE AND                |        |   500 | 10000 |   231   (1)| 00:00:01 |KEY(AP)|KEY(AP)|
|*  6 |     TABLE ACCESS FULL                 | MAIN_T |   500 | 10000 |   231   (1)| 00:00:01 |KEY(AP)|KEY(AP)|
----------------------------------------------------------------------------------------------------------------
 
Predicate Information (identified by operation id):
---------------------------------------------------
 
   1 - filter(TRUNC(SYSDATE@!)+10>=TRUNC(SYSDATE@!))
   4 - access("B"."DAY_ID">=TRUNC(SYSDATE@!) AND "B"."DAY_ID"<=TRUNC(SYSDATE@!)+10)
   6 - filter("A"."DATE_ID"="B"."DAY_ID" AND "A"."DATE_ID"<=TRUNC(SYSDATE@!)+10 AND 
              "A"."DATE_ID">=TRUNC(SYSDATE@!))
 
Note
-----
   - automatic DOP: Computed Degree of Parallelism is 1 because of parallel threshold
   - this is an adaptive plan

granularity => 'ALL'