Github user afs commented on a diff in the pull request: https://github.com/apache/jena/pull/423#discussion_r189391030 --- Diff: jena-db/jena-dboe-transaction/src/main/java/org/apache/jena/dboe/transaction/txn/TransactionCoordinator.java --- @@ -88,6 +89,22 @@ // See also {@code lock} which protects the datastructures during transaction management. private ReadWriteLock exclusivitylock = new ReentrantReadWriteLock() ; + // The version is the serialization point for a transaction. + // All transactions on the same view of the data get the same serialization point. + + // A read transaction can be promoted if writer does not start + // This TransactionCoordinator provides Serializable, Read-lock-free + // execution. With no item locking, a read can only be promoted + // if no writer started since the reader started or if it is "read committed", + // seeing changes made since it started and comitted at the poiont of promotion. + + /* The version of the data - incremented when transaction commits. + * This is the version with repest to the last commited transaction. + * Aborts do not cause the data version to advance. + * This counterr never goes backwards. --- End diff -- lang="pirate"
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