Insert data from remote table takes too long to finish

Question

When i execute this query

Select * 
  from remote_tabe@my_db_Link 
 where Update_Date >= to_Date( sysdate - 1/24 )

it returns around 4000 rows by 30 secs

but when i execute the insert statement

Insert into my_table 
    select * 
      from remote_tabe@my_db_Link 
     where Update_Date >= to_Date( sysdate - 1/24 )

it takes more than 3 hours! Can anybody please help in solving this issue?

Answer 1

It is possible that the execution plans are different for the two queries. Have you checked, using DBMS_Xplan?