first fifty blocks...2

Although I started with the title of this series of posts as 'first fifty blocks', obviously inspired by the movie (First Fifty Dates) I realize that the bulk of the information resides in the initial blocks. The first block is the data file header followed by Bitmapped File Space Header at Block 2. These two blocks are followed by the extent bitmaps that are described in detail at Oak Table Network by Connor McDonald way back in 2003.
Apart from changes in the SCN (system change number), one also sees that the RDBA (Relative Data Block Address) changes when a table is created in the tablespace. This is accompanied by changes in Memory addresses. Also initially when the blocks are not used they do not receive a File ID (compare the bold File/Block values in the table in the previous post) and are marked as 'unknown' type. Disturbingly, one sees the dreaded word 'CORRUPT'. When the table is created these block id's are associated with the File ID and receive valid RDBAs and different memory addresses.