What do you mean "dont have RMAN" ? *Every* Oracle database has RMAN.
If you are saying "we are not ALLOWED to use RMAN"...well that's a different story, and a pretty sad one at that. Because that's like saying "We need to remove some rows, but are not allow to use DELETE".
Why invest in a product like the Oracle Database and then not take advantage of its features?...That's madness.
Anyway...if you want burn up resources and outage windows using non-RMAN methods, I guess I can't stop you.
A CTAS lets you pull blobs across the network, for example
SQL> desc supporting_files@np12
Name Null? Type
----------------------------------------------------------------------- -------- ------------------------------------
ID NOT NULL NUMBER
DESCRIPTION VARCHAR2(4000)
ADMIN_ID NOT NULL NUMBER
FILE_CONTENT BLOB
FILE_NAME VARCHAR2(255)
FILE_MIME_TYPE VARCHAR2(255)
FILE_CHARACTER_SET VARCHAR2(255)
FILE_UPDATED_DATE TIMESTAMP(6) WITH LOCAL TIME ZONE
FILE_SIZE NOT NULL NUMBER
ROW_VERSION NOT NULL NUMBER
CREATED_ON NOT NULL TIMESTAMP(6) WITH LOCAL TIME ZONE
CREATED_BY NOT NULL VARCHAR2(255)
MODIFIED_ON NOT NULL TIMESTAMP(6) WITH LOCAL TIME ZONE
MODIFIED_BY NOT NULL VARCHAR2(255)
mcdonac@db11
SQL> select count(*) from asktom.ate_supporting_files@np12;
COUNT(*)
----------
1
SQL> create table local_blob_copy as select * from supporting_files@np12;
Table created.
So you could do this in parallel, or your own parallelism, ie, multiple CTAS's running in parallel, each with a different WHERE clause to pull over different chunks of the table.
Hope this helps.