topic Re: Enqueue Modes in Application Development and Automation Discussions

Enqueue Modes

Former Member — Fri, 15 Dec 2006 21:20:55 GMT

What do we mean by different mode on Enqueue E, X and S.

Does it mean that one mode will lock permanenetly and other will not ?

Please guide.

Regards,

Rajesh

Re: Enqueue Modes

suresh_datti — Fri, 15 Dec 2006 21:25:17 GMT

Pl check this <a href="http://help.sap.com/saphelp_erp2005vp/helpdata/en/9a/49d91d498b4e489eef193e949db3f7/frameset.htm">SAP Help</a>

~Suresh

Re: Enqueue Modes

Former Member — Fri, 15 Dec 2006 21:26:16 GMT

Types of locks

You can lock the table or record by using following types of locking:

1) Exclusive (E) the locked data can only be displayed or modified by single user i.e the owner of the object. Access to other users is denied.

2) Shared (S) several users can access the same record simultaneously, but only in display mode and except the first one, who has asked for the data in update mode.

3) Exclusive not cumulating (X) it is similar to exclusive lock. It allows only a single user access. E can be called several times from the same transaction. In contrast, a lock type X can be called only once during the transaction. Any other call for this lock is rejected.

Activation of Lock Object

1) When you activate the lock object, the functions are automatically generated. And these are ENQUEUE-EZN and DEQUEUE-EZN. EZN is name of the lock object.

2) While ENQUEUE is used in program to set the code over the selected data depending upon the lock object arguments. DEQUEUE is used to release the lock.

- Guru

Reward points for helpful answers

Re: Enqueue Modes

Former Member — Fri, 15 Dec 2006 21:27:21 GMT

Hi,

Check this documentation..

Exclusive lock

The locked data can be read or processed by one user only. A request for another exclusive lock or for a shared lock is rejected.

Shared lock

Several users can read the same data at the same time, but as soon as a user edits the data, a second user can no longer access this data. Requests for further shared locks are accepted, even if they are issued by different users, but exclusive locks are rejected.

Exclusive but not cumulative lock

Exclusive locks can be requested by the same transaction more than once and handled successively, but an exclusive but not cumulative lock can only be requested once by a given transaction. All other lock requests are rejected.

THanks,

Naren