事务，锁，块，rowid 的关系图示

ncgxq

这是我找到的有关ITL的文档，好象有点老了

==> Transaction table (below) controls concurrency:
==>        Itl        ITL Index no   (No ITLS determined by INITRANS and MAXTRANS)
==>        Xid        Transaction ID (UndoSeg.Slot.Wrap)
==>        Uba        Undo Address   (UndoDBA.SeqNo.RecordNo)
==>        Flg        C = Committed        U = Commit Upper Bound        T = Active at CSC       
                B = Rollback of this UBA gives before image of the ITL.
      Flag combinations include:
        CB--        Tx is committed, Rollback of this UBA gives previous ITL.
        ----        Active TX - look at RBS header to see if really active.
        --U-    If lck=0 block is cleaned out with Upper Bound Commit.
                If lck!=0 (7.3) Scn is FSC.Scnbase. This is delayed logging.
                Block cleanout - see <Parameter: DELAYED_LOGGING_BLOCK_CLEANOUTS>
                The FSC cannot be discarded.
==>        Lck        No Rows affected by this transaction
==>        Scn/Fsc        Scn=SCN of commited TX, Fsc=Free space credit (bytes)
                Fsc overlaps the SCN Wrap when present.

ncgxq

终于找到这个文档了，看第三页的row header部分

ncgxq

还有这个PPT，也有一部分ITL的相关内容