Oracle Context equivalent for DB2 - oracle

Question

I am currently migrating from oracle to DB2. I have actively used sys_context in most of the applications to get the userID of logged in user through sessions(IIS and .net framework).
I am looking to convert the following set of scripts from oracle to DB2. So far not able to find any equivalent for oracle context in DB2.
SQL> create context my_ctx
2 using pkg_ctx;
Context created.
SQL> create package pkg_ctx
2 as
3 procedure set_context;
4 end;
5 /
Package created.
SQL> create or replace package body pkg_ctx
2 as
3 procedure set_context
4 as
5 begin
6 dbms_session.set_context( 'MY_CTX', 'USERNAME', 'test' );
7 end;
8 end;
9 /
Package body created.
SQL> exec pkg_ctx.set_context;
PL/SQL procedure successfully completed.
SQL> select sys_context( 'MY_CTX', 'USERNAME' )
2 from dual;
SYS_CONTEXT('MY_CTX','USERNAME')
-------------------------------------------------------------------------------
test

Answer 1

Assuming you work with Db2 for LUW, you can use one of the CURRENT CLIENT_* registry variables to pass session context information from the client application to the server. For example, during the session initialization on the client side you would issue SET CURRENT CLIENT_USERID='stacky', then on the server that variable can be read by a routine or a trigger.

Answer 2

It worked like this, haven't tried it at application level. But from the database tried to register 2 users from 2 different instances of the same database on DB2.
call sysproc.wlm_set_client_info('stacky',null,null,null,null);
select wlm_set_client_info from sysibm.sysdummy1;
returns stacky
from another instance of the same database
call sysproc.wlm_set_client_info('test',null,null,null,null);
select wlm_set_client_info from sysibm.sysdummy1;
returns test.
Will try this from the application level through creating sessions of the users, will monitor how exactly this works with the special registers.
Not sure if this is the exact way to do this, will explore more and keep updated.

Answer 3

For replicating a similar situation in our environment, while doing the migration from oracle to DB2 LUW.
The below procedure sets up the all the context values in user_id (limited to varchar 255) field which we need as as 'key1:value1|key2:value2|'
Procedure to setup the context values
CREATE OR REPLACE PROCEDURE setup_context(pValues IN VARCHAR)
IS
lValues VARCHAR2(255) := pValues;
BEGIN
--save the as is
wlm_set_client_info(lValues, NULL, NULL, NULL, NULL);
END;
Procedure to set the value of the desired key
CREATE OR REPLACE FUNCTION sys_context(prefix IN VARCHAR) RETURN VARCHAR IS
lValues VARCHAR2(255);
lParam VARCHAR2(255);
lKey VARCHAR2(255);
lValue VARCHAR2(255);
lIndex PLS_INTEGER;
BEGIN
--get the data from the current session
SELECT CURRENT CLIENT_USERID INTO lValues FROM dual;
LOOP
EXIT WHEN lValues IS NULL OR LENGTH(lValues) = 0;
lIndex := instr(lValues, '|');
IF lIndex > 0 THEN
lParam := substr(lValues, 1, lIndex-1);
lValues := substr(lValues, lIndex+1);
ELSE
lParam := lValues;
lValues := NULL;
END IF;
lIndex := instr(lParam, ':');
lKey := substr(lParam, 1, lIndex-1);
lValue := substr(lParam, lIndex+1);
--get the matching value
IF(lKey = prefix ) Then
RETURN lValue;
END IF;
END LOOP;
RETURN '';
END;
reference : https://www.ibm.com/support/knowledgecenter/en/SSEPEK_11.0.0/sqlref/src/tpc/db2z_sp_wlmsetclientinfo.html