SELECT *
FROM   tab
WHERE  col LIKE :this
OR     col LIKE :that

SELECT *
FROM   tab
WHERE  col LIKE :this

SELECT *
FROM   tab
WHERE  col LIKE :that

SELECT /*+USE_CONCAT*/ *
FROM   tab
WHERE  col LIKE :this
OR     col LIKE :that

 create table c_test ( A varchar(100) );

 insert into c_test select tname from tab;

 commit;


select A from c_test where a like 'A%' or a like 'B%'  

Statistics
----------------------------------------------------------
          1  recursive calls 
          0  db block gets
         10  consistent gets 
          0  physical reads
          0  redo size
       1003  bytes sent via SQL*Net to client
        261  bytes received via SQL*Net from client
          4  SQL*Net roundtrips to/from client
          0  sorts (memory)
          0  sorts (disk)
         39  rows processed


select /*+USE_CONCAT*/ A from c_test where a like 'A%' or a like 'B%' 

Statistics
----------------------------------------------------------
          4  recursive calls
          0  db block gets
         18  consistent gets 
          0  physical reads
          0  redo size
       1003  bytes sent via SQL*Net to client
        261  bytes received via SQL*Net from client
          4  SQL*Net roundtrips to/from client
          0  sorts (memory)
          0  sorts (disk)
         39  rows processed

select a from c_test where regexp_like(a,'^[AB]');