Linker IT Software
menubar-top-links menubar-top-rechts
Home Help Search Login
Welcome, Guest. Please Login.
SQL*XL: Database to Excel bridge litLIB: Excel power functions pack ExcelLock: Locking and securing your valuable Excel spreadsheets encOffice: Protect your Excel file easy and safe encOffice: Protect your Excel file easy and safe
Pages: 1
Distributed and In-Doubt Transactions (Read 1418 times)
Gerrit-Jan Linker
YaBB Administrator

Posts: 75
Distributed and In-Doubt Transactions
21.12.11 at 13:38:44
Distributed and In-Doubt Transactions
In  a distributed transaction the integrity is ensured by Oracle's two-phase commit mechanism. In the prepare phase, the initiating node in the transaction asks the other participating nodes to promise to commit or roll back the transaction. During the commit phase, the initiating node asks all participating nodes to commit the transaction. If this outcome is not possible, then all nodes are asked to roll back.
If the transaction fails because of a system or network error the transaction becomes in-doubt.
Distributed transactions can become in-doubt in the following ways:
  • A server machine running Oracle software crashes.  
  • A network connection between two or more Oracle databases involved in distributed processing is disconnected.  
  • An unhandled software error occurs.  
    The RECO process automatically resolves in-doubt transactions when the machine, network, or software problem is resolved. Until RECO can resolve the transaction, the data is locked for both reads and writes. Oracle blocks reads because it cannot determine which version of the data to display for a query.
    Oracle database links survival guide
    Two-Phase Commit Mechanism
  • Back to top

    Gerrit-Jan Linker
    Linker IT Software
    Email WWW Gerrit-Jan Linker   IP Logged
    Pages: 1