Oracle Database – Remove Windows NTFS Compression from Datafiles

Assuming you have the appropriate DBA-level permissions, you can try this to get some basic information on the SecureFile/LOBs in your system:

SELECT table_name, segment_name, index_name, securefile, in_row
FROM user_lobs;

You can get the size on disk for a specific table name (your table with a SecureFile/LOB) by doing this:

SELECT segment_name, segment_type, segment_subtype, bytes/1024/1024 meg_bytes
FROM user_segments
WHERE table_name = 'yourTableName';

To get the actual compression rating (no/low/high), try this using your table name:

SELECT table_name, column_name, partition_name, tablespace_name, compression, deduplication
FROM user_lob_partitions
WHERE table_name = 'yourTableName';

Hope this helps!

Seeing as you have stated that the original data files look like they're untouched, all you need to do is recreate the service with oradim, making sure you're using the 9i ORACLE_HOME service and tools.