topic Re: lock object in Application Development and Automation Discussions

lock object

Former Member — Mon, 27 Aug 2007 06:45:46 GMT

Hi all,

can anyone tell me diff betn exclusive lock & exclusive but not cumulative lock

Re: lock object

Former Member — Mon, 27 Aug 2007 06:58:10 GMT

Lock mode E: This sets a lock for changing data for single user. This lock can be accumulated.

Lock mode X: This mode is used like mode E for changing data. The only technical difference from mode E is that the respective lock does not allow accumulation.

Lock mode S: This mode ensures that data displayed in your program cannot be changed by other users during the entire display time. Here you do not want to change the data yourself (allows read only access for data).

reward if usefull

Re: lock object

Former Member — Mon, 27 Aug 2007 08:10:30 GMT

Hi,

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.

Also check the following

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.

You can create a lock on a object of SAP thorugh transaction SE11 and enter any meaningful name start with EZ Example EZTEST_LOCK.

Use: you can see in almost all transaction when you are open an object in Change mode SAP could not allow to any other user to open the same object in change mode.

Example: in HR when we are enter a personal number in master data maintainance screen SAP can't allow to any other user to use same personal number for changes.

Technicaly:

When you create a lock object System automatically creat two function module.

1. ENQUEUE_<Lockobject name>. to insert the object in a queue.

2. DEQUEUE_<Lockobject name>. To remove the object is being queued through above FM.

Lock objects:

http://www.sap-img.com/abap/type-and-uses-of-lock-objects-in-sap.htm

http://help.sap.com/saphelp_nw04s/helpdata/en/cf/21eea5446011d189700000e8322d00/content.htm

Create lock object.

GO TO SE11

Select the radio button "Lock object"..

Give the name starts with EZ or EY..

Example: EYTEST

Press Create button..

Give the short description..

Example: Lock object for table ZTABLE..

In the tables tab..Give the table name..

Example: ZTABLE

Save and generate..

Your lock object is now created..You can see the LOCK MODULES..

In the menu ..GOTO -> LOCK MODULES..There you can see the ENQUEUE and DEQUEUE function

http://help.sap.com/saphelp_nw04/helpdata/en/cf/21eea5446011d189700000e8322d00/content.htm

<b>Reward if helpful.</b>

Re: lock object

Former Member — Mon, 27 Aug 2007 09:47:23 GMT

what is a match code ? Lock objects ?

The MATCH CODE is nothing but a DDIC search help. If you want to assign a search help to a PARAMETERS or SELEC-OPTIONS in your report program you can use MATCH CODE followed by name of the DDIC search help. Make sure that the DATA ELEMENTS are matched when you make the assignment.

for more information on search help please referr the following link it help you

http://help.sap.com/saphelp_nw04/helpdata/en/cf/21ee2b446011d189700000e8322d00/content.htm

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.

You can create a lock on a object of SAP thorugh transaction SE11 and enter any meaningful name start with EZ Example EZTEST_LOCK.

Use: you can see in almost all transaction when you are open an object in Change mode SAP could not allow to any other user to open the same object in change mode.

Example: in HR when we are enter a personal number in master data maintainance screen SAP can't allow to any other user to use same personal number for changes.

Technicaly:

When you create a lock object System automatically creat two function module.

1. ENQUEUE_<Lockobject name>. to insert the object in a queue.

2. DEQUEUE_<Lockobject name>. To remove the object is being queued through above FM.

regards,

srinivas

<b>*reward for useful answers*</b>