Transfering tables between databases

Question

I have some tables in an Oracle database that I have to copy (for tests) to another Oracle database resident on another computer without compromising the first database in any way.
How can I do this? Is there a friendly (and straightforward process) ?

Answer 1

Hi,
Apart from the three methods what Mr.Lijesh Kalavara has stated, i feel COPY command can be another option.
It copies data from a query to a table in a local or remote database location.
Set arraysize and set copycommit controls the transactions commit batch mechanism.
sql> SET ARRAYSIZE <Number Of Records in each batch>
set arraysize 1000 determine the 1000 records of the total records will be retrieved in each batch.
sql> SET COPYCOMMIT <Number of batches should be commited at one time>
set copycommit 1 indicates one batch should be commited at a time.
So if we are inserting 100,000 records then data will commit after inserting 1000 records every time.
If you have a small rollback segment , set arraysize to less number of records and copycommit to 1.
Syntax :-
usage: COPY FROM <db> TO <db> <opt> <table> { (<cols>) } USING <sel>
<db> : database string, e.g., scott/tiger@d:chicago-mktg
<opt> : ONE of the keywords: APPEND, CREATE, INSERT or REPLACE
<table>: name of the destination table
<cols> : a comma-separated list of destination column aliases
<sel> : any valid SQL SELECT statement
Append : - Create table in the destination if it does not exist and ignore if it exist and insert rows
Create :- Create table in the destination and insert rows
Insert :- insert the rows only . Error occurs if the table does not exist.
Replace :- Drop the existing destination table and creates new table with data.
e.g.
set copycommit 100 arraysize 1000 buffer 100000
COPY FROM schema1/password@Db1 TO schema2/password@db2
insert table_in_db2 (column1, column2) USING SELECT * FROM table_in_db1;
COPY supports the following datatypes:
CHAR
DATE
LONG
NUMBER
VARCHAR2
By using copy command you can reduce the burden on a rollback segment by dividing the entire inserting data into pieces or batches which commit individually and thus avoid of using large rollback segment.