You can copy data from one table to another by using one of following method, I assume that table structure of both tables are identical and thier datatypes as well or atleast should be compatible.
as long as you are not tryinh to copy long or bfile datatypes and the database is same, the following command suppose to work. <schemaname> is optional, if you are copying data of one table to another in the same schema.
SQL>insert into table b (select * from schemaname.a)
If your databses are different then first create the databse link to make use <Method 1>, all restriction will be applied.
SQL>create public database link scott.com
2>connect to scott identified by tiger
If you dont want to make a public database link, omitt the public keyword from the above command.
now use the <method1> as follows:
SQL>insert into table b (select * from firstname.lastname@example.org
SQL>COPY FROM scott/tiger@ORCL -
TO scott/tiger@ORCL2 -
REPLACE b -
USING SELECT * FROM a
copy command will replace the table if it is already exist and keep the column names and thier data types identical to source table.
<copy> command create the table in your schema itself, and keep the datatype of each column identical