Interface ReadGuarantees

All Known Implementing Classes:
TransactionConcurrencies.Guarantees
public interface ReadGuarantees
Guarantees for existing rows successfully returned by a read. A false answer means that callers must not rely on the guarantee. Changes made by the reading transaction itself are excluded.
Since:
8.0

  • Method Summary

    Modifier and Type
    Method
    Description
    boolean
    hasStableRowView()
    Whether later reads of the same kind preserve values and existence of previously read rows until transaction completion.
    boolean
    holdsRowLockUntilTransactionCompletion()
    Whether a row lock is acquired and retained until transaction completion.
    boolean
    isCurrentRead()
    Whether a successful read observes current committed row state, waiting for the outcome of a conflicting uncommitted write rather than returning an older snapshot.
    boolean
    preventsConcurrentModification()
    Whether other transactions are prevented from modifying or deleting returned rows until transaction completion.
    boolean
    preventsDirtyReads()
    Whether values written by other uncommitted transactions are excluded.

  • Method Details

    • preventsDirtyReads

      boolean preventsDirtyReads()
      Whether values written by other uncommitted transactions are excluded.

    • hasStableRowView

      boolean hasStableRowView()
      Whether later reads of the same kind preserve values and existence of previously read rows until transaction completion. A snapshot may provide this without preventing concurrent modification.

    • preventsConcurrentModification

      boolean preventsConcurrentModification()
      Whether other transactions are prevented from modifying or deleting returned rows until transaction completion. Snapshot stability or a possible later serialization failure is insufficient.

    • holdsRowLockUntilTransactionCompletion

      boolean holdsRowLockUntilTransactionCompletion()
      Whether a row lock is acquired and retained until transaction completion.

    • isCurrentRead

      boolean isCurrentRead()
      Whether a successful read observes current committed row state, waiting for the outcome of a conflicting uncommitted write rather than returning an older snapshot. A conflict may instead fail the operation. This does not promise that the state remains unchanged after the read.