Rowid Format has a "/" (Forward Slash) - WHY?

Posted on 2006-05-03
Last Modified: 2012-06-27


As per my knowledge ROWID is a HEX value and should not have a "/" (Forward Slash) in it. I have not found any documentation in Oracle on this.

1. This is a normal TABLE.
2. ROWID has ONE or TWO "/" Forward Slash characters.

Any one knows why?

Sudhakar Kotagiri
Question by:skotagiri123
    LVL 34

    Accepted Solution

    Which version of Oracle do you have? Oracle changed the format of rowid between Oracle8i and Oracle9.  In Oracle9i and 10g, the rowid is not expressed in HEX by default.
    LVL 19

    Assisted Solution

    ROWID is a datatype. What we normally see is a form which has been transformed by Oracle.

    What we see here is an extended ROWID. internally it has 10 bytes.The extended ROWID pseudocolumn is returned to the client in the form of an 18-character string (for example, "AAAA8mAALAAAAQkAAA"), which represents a base 64 encoding of the components of the extended ROWID in a four-piece format, OOOOOOFFFBBBBBBRRR:

        * OOOOOO: The data object number identifies the database segment (AAAA8m in the example). Schema objects in the same segment, such as a cluster of tables, have the same data object number.
        * FFF: The datafile that contains the row (file AAL in the example). File numbers are unique within a database.
        * BBBBBB: The data block that contains the row (block AAAAQk in the example). Block numbers are relative to their datafile, not tablespace. Therefore, two rows with identical block numbers could reside in two different datafiles of the same tablespace.
        * RRR: The row in the block (row AAA in the example).
         So it is not HEX number and it could be any character in the returned format.


    Author Comment

    Sorry for the delay. Moved to a new project. My question is :

    What are "/" also part of the POWID returned? This is found in the return FORMAT.

    LVL 34

    Expert Comment

    by:Mark Geerlings
    Did you notice my earlier question: "Which version of Oracle do you have?"

    That *DOES* make a difference, since Oracle changed the format for displaying the value of ROWID after Oracle8i.
    LVL 34

    Expert Comment

    by:Mark Geerlings
    Just FYI, here is a partial result of:
    select rowid from [one of our tables]

    So, in Oracle10.1 at least, it is not unusual to see non-numeric, and non-alphabetic characters displayed in the ROWID.
    LVL 19

    Expert Comment

    As I said, no document claims that ROWID must be showed in hexadecimal form and therefore it is not strange to see "/" or "+" appearing along with "W" "g" which are also not hex.
    LVL 19

    Expert Comment

    I hope that I can find the algorithm to transfer internal content but as Mark listed they certianly don't restrict them  to alphanumeric.

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