Re: Using DD to Read Data from Oracle Datafiles

  • From: Steve Adams <steve.adams@xxxxxxxxxxxx>
  • To: naqimirza@xxxxxxxxx
  • Date: Wed, 07 Feb 2007 20:18:24 +1100

Hi Naqi,

The numbers are stored in a coded format. Check the Oracle documentation for the format, or Google for it on various other web sites.

You also need to ensure that you consult the row directory in the block to find valid row offsets, the ITLs and corresponding undo segments to check for transactional integrity, and so on. Just using strings, even for purely text data, is not reliable.

@   Regards,
@   Steve Adams
@   Oracle-L List Administrator
@         - For DBAs
@  - For all

Naqi Mirza @ 7/02/2007 7:15 PM:
I am using dd to read data out of oracle datafiles from an oracle 9i database on solaris. I am using the following command:

dd if=/location_to_oracle_datafile_and_file_name.DBF bs=8192 skip=11764 count=8 | strings

I have a table called DEPT, querying dba_extents, I see that its block_id is 11764. It also have 8 blocks assigned to it. Now using the above, I get the following output:


Whats missing from here is numeric values. Since I am piping the output to strings , strings will not print out numerics. Does anyone know how i can use the method above to successfully read an entire table and print out all its comments.

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