How to lock a table

Hi all,
When I insert a record to a table , how to lock it for
preventing others write the table at the same time?
Thanks.

If you want to use online documentation, go to
http://tahiti.oracle.com
and search for "lock table"

Similar Messages

How to lock a table when i insert a row

hi, friends,
how to lock a table when i insert a row, then unlock the table

If you want to lock the whole table so that no-one else can do DML then you go LOCK TABLE <table> IN EXCLUSIVE MODE. This lock remains in force until you commit or rollback.
There are less powerful locking modes available, but you can look those up in the OTN online documentation.
APC

How to lock a table in a report program

Hi all,
I have a requirement inwhich if i have selected one radio button the table should locked .
and the i need to check wether the table is locked or not by checking the condition.if locked continue else i need to stop.
can any one help me doing this.

Hi,
Hope this information will be useful for you.....
The description of an SAP lock to a table is made via the lock condition and the lock mode.
The lock condition is a logical condition for the lines of the table to be locked. It describes the area of the table which the lock is to protect from competitive access. To avoid the administration of the lock becoming complicated, the lock condition can not be formulated as freely as the WHERE clauses: only fully qualified key fields related by AND may appear in the condition.
Via the lock mode you define which operations on the table are to be protected by the lock. The lock modes available are:
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.
In order to be able to define SAP locks for a table, you must first create a lock object for the table via Development->Dictionary.
If the data for an application object is distributed among several database tables, it is often necessary to be able to lock these tables simultaneously. It is therefore possible to include several tables in a lock object, althought they must be related via appropriate foreign key relationships. The tables involved in a lock object are also known as its base tables.
Thanks
NITESH

How to LOCK a table in SAP?

Hi,
Just wondering is there a way we can lock a table in SAP?
tcode or something?
ex. there a tcode to lock tcodes (SM01)
so wondering if there is a tcode or another method?
Thanks!

Hi,
These are application locks not the database tables lock.
If you use this function modules (enqeue and dequeue)
then only it works the concept of locking.If you dont use this fms then you can directly access the table.
If I am the developer and I dont implement the locks then no locking concept would happen.
Regards,
Vamshi.

How oracle locks child table with foreign keys?

I have 3 tables. tab1 , tab2,tab3.
tab2 has FK on tab1.
tab3 has FK on tab2.All the FKs are indexed.
One transaction in my code changes tab3.
One transaction in my code changes tab1,tab2 and tab3.
I am facing deadlock issues on tab3 when both transactions work concurrently.
If I lock tab1 with "for update nowait " at the start of both transaction,will the problem be solved?

Let me elaborate on my problem
TAB1
=====
a1 b1 c1
a2 b2 c2
a3 b3 c3
TAB2
=====
x1 y1 z1 a1
x2 y2 z2 a2
x3 y3 z3 a3
(FK indexed)
TAB3
=====
p1 q1 r1 y1
p2 q2 r2 y2
p3 q3 r3 y3
(FK indexed)
Transaction 1 for session1
select * from TAB1 where col1 = a1 for update nowait;
doing activities on tab2 and tab3 depending on the foreign key joins in loop.
Transaction 2 for session 2
select * from TAB1 where col1 = a2 for update nowait;
doing activities on tab2 and tab3 depending on the foreign key joins in loop.
1) Please let me know whether these sessions can head towards deadlock.
2) If some session try to update TAB3 row of y1 when session 1 is still working , how will system behave?
will it go for blocked session or go for dead lock or get an exception message?
Edited by: user9974355 on Dec 17, 2008 11:58 PM
Edited by: user9974355 on Dec 18, 2008 12:00 AM

How to lock a table/record from being read

Hi,
We are facing a problem executing a backend operation due to the presence of 2 JVMs.
We have a set of batch jobs that needs to run on a daily basis. We are using a flag in a table to check if any job is currently running, based on which the job is kicked off.
The problem comes up when the 2nd JVM tries to read the same data present in the table and kicks off the job, which it shouldnt.
Currently this is how i am implementing it:
SELECT COUNT(1) into l_status FROM Log_Table
where job_status is NULL
FOR UPDATE;
IF (l_status = 1) THEN
UPDATE Log_Table
SET Job_Status = 'In_Execution'
WHERE Job_status = NULL; -- Only 1 rec will contain this field as NULL
END IF;
COMMIT;
l_status decides whether the job should run or not.
SELECT..FOR UPDATE does not stop the 2nd JVM from reading the data (or will it?). The 2nd JVM will just wait for the lock to be released, execute the UPDATE without knowing the current value of Job_Status and then start the batch job. Correct me if my knowledge of SELECT FOR UPDATE is wrong.
What can be done to completely avoid the 2nd JVM from intervening?
Solutions would be much appreciated.

I have dealed with your problem. Please checkout thread Is it possible to pevent select operation on a table?

How to lock DB table

Hello, I'm using EclipseLink 1.2 (I hope I've chosen right forum branch). I need to lock a DB table.
I know there are some methods like lock(), refresh(), find() with LockModeType enum parameter. I know that I can lock all rows returned with a query if I use parameter LockModeType. But I need to lock table fully for insert, update and delete. Besides, I need to lock table not from object model only, but to lock it within DB.
Now I'm executing pl/sql procedure in my method start:
CREATE OR REPLACE PROCEDURE TEST_ME (N NUMBER) AS
BEGIN
LOCK TABLE some_table IN EXCLUSIVE MODE NOWAIT;
END TEST_ME;
/Is this the only way?

Hello,
I'm not sure I understand the reasoning why you want to lock the entire table, or what you mean when you say it needs to be locked within the database. Pessimistic locking though is generally not the prefered option so if what you are looking for is not available in LockModeType, then of course you can execute SQL or a stored procedure to get a lock directly. I do not know of any other ways to get what you describe - I would recommend avoiding pessmistic locking altogether if possible though.
Best Regards,
Chris

How to Lock a data base table for write access.

Hi All,
I have a requirement where in I have to insert a bunch of data into a standard table using some function module. I want to lock the table for the others to insert/modity the records during my insertion. Please help me provide the procedure how to lock a table for write access for others.
thanks and regards,
Naresh

Hi,
See to this link it may help you.
http://help.sap.com/saphelp_47x200/helpdata/en/af/22ab01dd0b11d1952000a0c929b3c3/frameset.htm
http://help.sap.com/saphelp_47x200/helpdata/en/af/22ab01dd0b11d1952000a0c929b3c3/frameset.htm

Locking the table

Hi folks,
I am new to using Numbers, or any spreadsheet for that matter, so I'm pretty baffled.
I created a table to use in my lesson planning, as I found inserting a table into a Pages document didn't serve my purposes. The table looks great, but here's my problem:
I created a large area in the middle of the page in which to type text by merging a whole whack of cells. I did this as it seemed like the best way to create a large area but still maintain the integrity of the format of the page. The problem, however, is that I have no clue how to lock the table - to set the table so that none of the cells change size when I insert text. I have been typing in the text, and the cell keeps expanding, and I have no idea why - I haven't reached the "end" of the cell so I'm not sure why it's not just staying the same size.
I tried to read through the user guide, but I wasn't able to find what I'm looking for.
Thanks folks,
Shawn

Shawn,
Without knowing more about why you need a large text area in the middle of your table, it's a little difficult to suggest solutions. In general though, it's not a good idea to Merge Cells just for visual effect. Having affected all those rows and columns will cripple any future efforts to sort the table, or to add or delete rows and columns. You could Insert a Text Box and put your prose there. Position the text box anywhere you like - even over the middle of the table - without causing any future problems with the table.
Generally we want table cells to expand when we run out of room while making input. I assume that you already have turned on the Wrap feature in the Cells Inspector so that you get more than one line in the cell. You can begin with an oversize cell by dragging the borders of the labels. Beyond that, with Wrap turned on, Numbers will (as you have noticed) accommodate all your input by expanding the height of the cell.
Jerry

Locking source tables during process flow

Hi All,
I have a process flow which calls multiple mappings and stored procedures. I pull data from source located in different database and insert data into current database. Since, this migration is delta migration, I want to make sure that during migration, no user should add data into source till migration is successfully completed.
I had called a procedure which locks individual tables, but as soon as next mapping is completed the lock gets released, since each mappings commits data. I want that the lock should be active till all mappings gets completed.
Regards,
Danish

Commit will release all locks. Therefor, no matter how you lock the table, the lock will release when you commit the map. An alternative might be to capture a frozen image of the data into a local GTT created with the on commit preserve rows option.

How to see lock on table and query?

Hi All,
How do we see lock on table and query?
Thanks,
Rafi

Yes Rafi,
It is working fine at my end. See below:
Opened Session 1 with scott/tiger and:
update emp set ename='xx' where empno=7499;
Opened Session 2 with scott/tiger and:
update emp set ename='xx' where empno=7499;
<<Its lock here>> This session is locked by above one.
Opened Session 3 with sys/pw as sysdba and:
SQL> set serveroutput on
SQL> BEGIN
2 dbms_output.enable(1000000);
3 for do_loop in (select session_id, a.object_id, xidsqn, oracle_username, b.owner owner,
4 b.object_name object_name, b.object_type object_type
5 FROM v$locked_object a, dba_objects b
6 WHERE xidsqn != 0
7 and b.object_id = a.object_id)
8 loop
9 dbms_output.put_line('.');
10 dbms_output.put_line('Blocking Session : '||do_loop.session_id);
11 dbms_output.put_line('Object (Owner/Name): '||do_loop.owner||'.'||do_loop.object_name);
12 dbms_output.put_line('Object Type : '||do_loop.object_type);
13 for next_loop in (select sid from v$lock
14 where id2 = do_loop.xidsqn
15 and sid != do_loop.session_id)
16 LOOP
17 dbms_output.put_line('Sessions being blocked : '||next_loop.sid);
18 end loop;
19 end loop;
20 END;
21 /
Blocking Session : 139
Object (Owner/Name): SCOTT.EMP
Object Type : TABLE
Sessions being blocked : 134
PL/SQL procedure successfully completed.HTH
Girish Sharma

How to lock a database Z table before updating it through a report program

Hi,
How to lock a database Z table before updating it through a report program and also how to unlock it after my updation.
The whole process is done through report program.

Hi,
Go to SE11, in the option 'Lock object' enter the name of your lock,
begin with 'E', suppose 'EXXXX' And create. In tab 'Tables' fill the
table name where the record you want to lock exist and select the
lock mode. Lock mode can be shared and exclusive. If 'shared',
when you lock the record, other can also read data, but can not
modify. If 'exclusive', when you lock the record, other can neither
read nor modify the record. After save and activate, you will get two
function module.'ENQUEUE_EXXXX' to lock record,
'DEQUEUE_EXXXX' to release lock on one record.
When use this function module it only lock one record at a time. It
does not lock the table.
Regards,
Omkaram.

How can we lock the table?? how can we lock the record

Hi
how can we lock the complete table?? how can we lock the record ?/
Thanks
Rama

Lock objects are used to lock the database table while making the modifications on the database table.
you can create your own lock objects using SE11.
if you create lock objects on any table system will create two function modules.
1.ENQUEUE....
2.DEQUEUE.....
first one is used to lock the table
second one used to removing lock on the table.
lock Table
CALL FUNCTION 'ENQUEUE_E_TABLE'
EXPORTING
tabname = table_name
EXCEPTIONS
foreign_lock = 1
system_failure = 2
OTHERS = 3.
Unlock Table
CALL FUNCTION 'DEQUEUE_E_TABLE'
EXPORTING
tabname = table_name
check this link :
http://help.sap.com/saphelp_40b/helpdata/en/cf/21eea5446011d189700000e8322d00/content.htm
_SCOPE = 1: The lock is not sent to the update program. The lock is removed when the transaction is ended.
_SCOPE = 2: The lock is sent to the update program. The update program is responsible for removing the lock. The dialog program which requested the lock no longer has an influence on the lock behavior. This is the standard setting for the ENQUEUE function module.
_SCOPE = 3: The lock
Re: lock objects
Reward if this helps.

How to lock the perticular record in table with some of fields

Hi,
I have one Doubt please clarify me.
How to lock the record in table with perticular fields combination please give me example of code.
Thanks,
Hari.

Hi,
IT LIKE this....
This is the function mode that you have to create for locking the contents of you internal table.
CALL FUNCTION 'ENQUEUE_EZHFINDID'
   EXPORTING
     mode_zhfindid        = 'E'
     mandt                = sy-mandt
     ownid                = w_display-ownid
X_OWNID              = ' '
_SCOPE               = '2'
_WAIT                = ' '
_COLLECT             = ' '
   EXCEPTIONS
     foreign_lock         = 1
     system_failure       = 2
     OTHERS               = 3.
CASE sy-subrc.
    WHEN 1.
      w_flag_lock = c_x.
     CLEAR w_okflag.
      MESSAGE e265 WITH w_display-ownnum.
ENDCASE.
Jayant Sahu.

How can I lock a table so that a person can only enter data, not manipulate the table?

I don't want to Lock the table as Numbers does it so perhaps locking is the wrong term. What I want to do is to lock the formatting of the table so it is possible to enter data but not possible to change the position, number of columns etc. I've been searching and all I can come up with is the regular lock function. But I still want to be able to use the cells. Just not change formatting.
Thanks, Brad

you cannot. When you lock a table the whole table is locked. I would consider segmenting the user input into a seprate, un-locked table and placing the calculations in a locked table

How to lock a table

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