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Abstract:
transaction may not precede all other operations of the subtransaction) in the L r model. If there are no integrity constraints between local and global data items, and global transactions have fixed-structure, then S is strongly correct. Proof We present the outline of the proof. In the L r model, since global transactions only read and write global data items, only global transactions write global data items, by Corollary 3, the global conjunct is preserved. Further, local transactions can be shown to read consistent global data items using Lemma 15 (since S can easily be modified to a schedule containing a single local transaction). Local conjuncts can be shown to be preserved using Corollary 4. Hence proved. 2 Corollary 7 Let S be a G2LPL schedule (in which the write on ticket i by a global subtransaction may not precede all other operations of the subtransaction) in the G rw L r model. If there are no integrity constraints between local and global data items, and both local and global transactions have fixed-structure, then S is strongly correct. Proof By induction, it can be shown that for an arbitrary operation p 2 S, 1. for all lt 2 L, if brelease(lt; p) and lt executes at a 2PL site, then read(lt
Citations
| 1319 | Concurrency Control and Recovery in Database Systems – Bernstein, Hadzilacos, et al. - 1987 |
| 23 | Multidatabase interoperability – Breitbart - 1993 |
