lock management

[Former Member]

dear friends,

could u plz tell me what is lock management and how mant types of locks are used and thge purposes

regards,

malli.

[Former Member]

The SAP system is equipped with a special lock mechanism that synchronizes access to data on the database. The purpose of the lock mechanism is to prevent two transactions from changing the same data on the database simultaneously.

Lock objects are use in SAP to avoid the inconsistancy at the time of data is being insert/change into database.

SAP Provide three type of Lock objects.

- Read Lock(Shared Locked)

protects read access to an object. The read lock allows other transactions read access but not write access to

the locked area of the table

- Write Lock(exclusive lock)

protects write access to an object. The write lock allows other transactions neither read nor write access to

the locked area of the table.

- Enhanced write lock (exclusive lock without cumulating)

works like a write lock except that the enhanced write lock also protects from further accesses from the

same transaction.

- Optimistic lock

Optimistic locks initially behave like shared locks and can be converted into exclusive locks.

You can create a lock on a object of SAP thorugh transaction SE11.

Have a look at below links. It will help you surely.

<a href="http://help.sap.com/saphelp_nw04s/helpdata/en/c2/2d7037ecc92a7ee10000009b38f8cf/content.htm">Lock Concept</a>

<a href="http://help.sap.com/saphelp_nw2004s/helpdata/en/cf/21eea5446011d189700000e8322d00/content.htm">Lock objects</a>

I hope it helps.

Best Regards,

Vibha

*Please mark all the helpful answers

[Former Member]

check this

http://help.sap.com/saphelp_47x200/helpdata/en/37/a2e3ae344411d3acb00000e83539c3/frameset.htm

regards

prabhu

[Former Member]

Check

Regards,

Santosh

[Former Member]

hi,

Lock objects are used to set locks on database tables. Usually the lock is applied using the key of the database table. This insures that only one user can change a specific record in a database table at one time. You create the lock object in SE11, once defined, there will be two function modules created, an ENQUEUE function module and a DEQUEUE function module. The naming convention is ENQUEUE_E<name of lock object>, DEQUEUE is the same, but replace ENQUEUE with DEQUEUE.

types:

Read lock (shared lock)

protects read access to an object. The read lock allows other transactions read access but not write access to the locked area of the table.

Write lock (exclusive lock)

protects write access to an object. The write lock allows other transactions neither read nor write access to the locked area of the table.

Enhanced write lock (exclusive lock without cumulation)

works like a write lock except that the enhanced write lock also protects from further accesses from the same transaction.

Reward if you find it helpful.

Thanx and regards,

pankaj singh