Nested Transactions I A nested transaction is a tree of transactions, the sub-trees of which are either nested or flat transactions.
{"Image DocumentName": "Nested Transactions IA nested transaction is a tree of transactions, the sub-trees of which are either nested or flat transactions.", "Image ImageDescription": "Transactions at the leaf level are flat transactions. The distance from the root to the leaves can be different for different parts of the tree. The transaction at the root of the tree is called top-level transaction, the others are called sub-transactions. A transaction s predecessor in the tree is called parent; a sub-transaction at the next lower level is also called a child. A sub-transaction can either commit or rollback; its commit will not take effect, though, unless the parent transaction commits. The rollback of a transaction anywhere in the tree causes all its sub-transaction to roll back. This combined with the previous point is the reason why sub-transactions have only ACI, but not D. \u00a9 Jim Gray, Andreas Reuter Transaction Processing - Concepts and Techniques WICS August 2 - 6, WICS 1999 Transaction Processing: Gray & Reuter.", "Image XResolution": "37", "Image YResolution": "37", "Image ResolutionUnit": "Pixels/Centimeter", "Image Software": "SlidePlayer", "Image YCbCrPositioning": "Centered"}