Oracle Database Discussions

dear all,

Please any one could help on this my problem is appreciated.......

i'm generating ticket numbers using stored procedure as below .

i need to know followings .....(i'm using oracle 10g)

1 .Does oracle stored procedure handle concurrency by default or does db manage concurrency when we using sps or do we have handle concurrency inside a stored procedure?
2.when i generating ticket no using this stored procedure is there any concurrency issue when 100 clients are access it concurrently???
3. Is there issue or bug in my java code??????????
4.I have already used select for update statement but when i used that in db rowlocks are hanging and db become stuck .........
SELECT serial_no into newSerial FROM SERIAL_TAB WHERE BR_CODE=xbranch AND SCH_CODE = xscheme for update;

could any one can help please................................

in my java code i use transaction and setAutoCommit(false) when calling this sp

public String getTicketNo(String br,String sch){

//getconnection
//setAutoCommit(False);
//call sp get return value ;
//commit;

//if error rollback transaction


}

create or replace PROCEDURE sp_generate_ticket (
xbranch in varchar,
xscheme in varchar ,
xresult OUT VARCHAR
) AS

BEGIN

-----------------------------------------------------------------------------------------------------------------------
newSerial:=0;


SELECT serial_no into newSerial FROM SERIAL_TAB WHERE BR_CODE=xbranch AND SCH_CODE = xscheme;

newSerial:=newSerial+1;

UPDATE SERIAL_TAB SET serial_no=newSerial WHERE BR_CODE=xbranch AND SCH_CODE = xscheme;


--- do other operations -------------------------------------------------------------------------------------

END;

Best Regards,
Pradeep.