The Oracle (tm) Users' Co-Operative FAQ

How do I dump a data block ?

Author's name: Norman Dunbar

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Date written: 18/02/2002

Oracle version(s): 8.0.5 onwards

How do I dump a data block ?

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How to determine which block to dump

Assuming you didn't have to dump the block because of an error message which said something like '... corrupt file number #f block number #b' - in which case you have your file and block numbers, you can extract the information from dba_segments.

How to dump the block

To dump a single block : alter system dump datafile <file_id> block <block_number>;

To dump a sequence of blocks : alter system dump datafile <file_id> block min <block_number> block max <block_number>;

The above commands can be replaced with a filename rather than an id : alter system dump datafile 'full_path_to_filename' block <block_number>;

Where does the blockdump go ?

The dump file is created in the user_dump_dest location as specified in initSID.ora..

And finally ...

Quote from MetaLink : The capability to generate a formatted block dump is primarily intended for use by Oracle Support and Development. There is no externally published information available on interpreting the contents of a blockdump and the information is considered 'internal' information.

Further reading:

Dumping an Oracle 8 block - from this very web site
Dumping an Oracle 7 block - and so is this !
Ixora - search for Blockdump to get a list of references, hints and tips.

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