db-derby-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Ravinder Reddy (JIRA)" <j...@apache.org>
Subject [jira] Created: (DERBY-3011) Implementing Speculative locking protocol to Derby
Date Wed, 15 Aug 2007 18:47:31 GMT
Implementing  Speculative locking protocol to Derby

                 Key: DERBY-3011
                 URL: https://issues.apache.org/jira/browse/DERBY-3011
             Project: Derby
          Issue Type: New Feature
          Components: Performance
            Reporter: Ravinder Reddy
            Assignee: Ravinder Reddy
            Priority: Minor

    Speculative Locking Algorithm is a Locking Protocol. All the currently available databases
are using 2-Phase Locking. The problem with 2 phase locking algorithm is, concurrency is less
and waiting time is more. On the other hand in Speculative Locking protocol waiting time has
been reduced drastically.

    In Speculative Locking algorithm the only waiting time is till the formation of last write
image of a data item in the database.
In Speculative Locking , a transaction releases the lock on the data object whenever it produces
corresponding after-image during it's execution. By accessing both before and after-images,
the waiting transaction carries out speculative executions
 and retains one execution based on the termination (commit or abort) mode of the  preceding

    By carrying out multiple executions for a transaction, SL increases parallelism without
violating serializability
criteria. Under the naive version of SL, the number of speculative executions of the transaction
explodes with data contention.

    Speculative Locking Protocol is a new Transaction management Protocol, which has not been
implemented yet in any of the Database Management systems available in the market. It has
been proved by various simulations that this Locking Protocol outperforms all the 2-Phase
Locking Protocols and their derivatives.

   This Locking Protocol when implemented in any Database Management System will bring revolution
in the Efficiency of DBMS and will become more robust.

This message is automatically generated by JIRA.
You can reply to this email to add a comment to the issue online.

View raw message