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• org.apache.derby.impl.store.raw.xact: Javadoc index of package org.apache.derby.impl.store.raw.xact.


Package Samples:

• org.apache.derby.impl.store.raw.xact

Classes:

• TransactionTable: The transaction table is used by the transaction factory to keep track of all transactions that are in the system. The transction table serves the following purposes: checkpoint - when a checkpoint log record is written out, it writes out also all transactions that have updated the database. RESOLVE: this is actually not used right now - rather, the transaction table is reconstructed during the redo phase by traversing from the undo LWM. It is a goal to use this transaction table (and traversing from the redoLWM) instead of rebuilding it to speed up recovery. Quiesce State - when a system enters ...
• XactXAResourceManager: The XactXAResourceManager implements the Access XAResource interface, which provides offline control over two phase commit transactions. It is expected to be used by TM's (transaction manager's), to recover if systems fail while transactions are still in-doubt (prepared). This interface allows access to commit,prepare,abort global transactions as part of a two phase commit protocol. These interfaces have been chosen to be exact implementations required to implement the XAResource interfaces as part of the JTA standard extension. It is expected that the following interfaces are only used during ...
• RowLocking1: A locking policy that implements row level locking with isolation degree 1. This is an implementation of Gray's degree 1 isolation, read uncommitted, or often referred to as dirty reads. Basically read operations are done with no locking. This locking policy is only to be used for read operations. The approach is to place all "write" container and row locks on the transaction group lock list. Locks on this group will last until end of transaction. This implementation will still get table level intent locks. This is to prevent hard cases where the container otherwise could be deleted while read ...
• RowLocking2: A locking policy that implements row level locking with isolation degree 2. The approach is to place all "write" container and row locks on the transaction group lock list. Locks on this group will last until end of transaction. All "read" container and row locks will be placed on a group list, key'd by the ContainerId of the lock. Locks on this list will either be released explicitly by the caller, or will be released as a group when the unlockContainer() call is made. Note that write operations extend from the RowLocking3 implementations.
• TransactionTableEntry: Transaction table entry is used to store all relavent information of a transaction into the transaction table for the use of checkpoint, recovery, Transaction management during Quiesce state, and for dumping transaction table. Only works with the following classes: TransactionTable, XactFactory, Xact During run time, whenever any transaction is started, it is put into the transaction table. Whenever any transaction is closed, it is removed from the transaction table.
• XactId: Use this class for a short hand representation of the transaction. This value is only guarentee to be unique within one continuous operation of the raw store, in other words, every reboot may reuse the same value. Whereas GlobalXactId is unique for all times across all raw store, a XactId is only unique within a particular rawstore and may be reused. XactId keeps track of the outstanding transactionId and is responsible for dispensing new transactionIds
• Xact: A transaction has five states CLOSED - cannot be used IDLE - no reads have been performed by the transaction. ACTIVE - at least one read has been attempted by the transaction UPDATE - at least one update has been attempted by the transaction PREPARED - the transaction is ready to commit (FUTURE). Transaction identifiers are re-used for transactions that do not enter the UPDATE state during their lifetime.
• RowLockingRR: A locking policy that implements row level locking with repeatable read isolation. Since phantom protection with previous key locking is actually handled by the upper level access methods, the only difference in repeatable read is that read locks are of type RowLock.RS2. This type will not conflict with a previous key insert lock.
• RowLocking2nohold: A locking policy that implements row level locking with isolation degree 2, never holding read locks after they are granted. Exactly the same as RowLocking2, except that read locks are acquired using zeroDuration locks, which are immediately released by the lock manager after they are granted.
• XactContext: The context associated with the transaction. This object stores the context associated with the raw store transaction on the stack. It stores info about the transaction opened within a context manager (ie. typically a single user) for a single RawStoreFactory.
• ContainerLocking2: A locking policy that implements container level locking with isolation degree 2.
• ContainerLocking3: A locking policy that implements container level locking with isolation degree 3.
• RowLocking3: A locking policy that implements row level locking with isolation degree 3.
• RowLocking3Escalate: A locking policy that implements row level locking with isolation degree 3.
• D_Xact: The D_Xact class provides diagnostic information about the Xact class.
• BeginXact: This operation indicates the beginning of a transaction.
• EndXact: This operation indicates the End of a transaction.
• NoLocking: A locking policy that implements no locking.
• EscalateContainerKey
• GlobalXactId
• InternalXact
• SavePoint
• LockCount
• XactFactory

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