Data Subsetting using MDW

Question

I am using Mobile Data Workbench to create data publications for users on win32 laptops.
While creating publication items, I would like to use parameters whose values I would like to specify using some variables, instead of manually keying them in for each user. Is there some way that I can specify the user name as the value for the parameter? Then I can use the same publication for multiple users and the data subsetting is done by the variable which gets its value dynamically from the user name to whom it is published.
Thanks for your replies

Answer 1

I have not done this with MDW as such, but to include user based data subserring do the following
1) work out how you are going to identify the records for a particular user for the publication items in question. I know this sounds a bit obvious, but it is worth giving this some thought. Is the data directly in the table/view the publication item is based on? do you need to include some subselect to obtain the correct values (consider building a database view to help with this)? are the columns and joins all indexed (otherwise you will have performance problems in the compose process/download)
2) the basic template given by the system for a publication item is 'SELECT * FROM <schema_owner>.TABLE' change this to something like one of the following (dependant on circumstance)
'SELECT * FROM <schema_owner>.TABLE where USER=:user'
'SELECT * FROM <schema_owner>.TABLE where ID IN (select id from <schema_owner.view where USER=:user)'
'SELECT t.* FROM <schema_owner>.TABLE t, <schema_owner>.TABLE2 t2 where t1.ID=t2.ID and t2.USER=:user'
all of these will work.
NOTE <schema_owner> is needed for ALL objects included in the template
NOTE the colon (:) used to identify the bind variable
3) publish the new/altered publication items, and you will find in the mobile manager that under the users>applications tab, there will be a link in the data subsetting tab (probably called the oracle lite client type). click on this and you will get a screen with all of the bind variables you have defined for the application, with a place to add in the values for that user.
Couple of points
a) all bind variables (or data subsetting parameters) are held and tested as VARCHAR2. If you are matching to numerics in the base tables, do 'where ID=TO_NUMBER(:user)' otherwise you will get typecasting and this will affect your performance
b) run conspef on the resultant publication items and check all parts for performance. The apply process uses the publication item priimary key for its selection, whilst the compose uses the selection criteria. You may need to tune for both options
c) you can include multiple subsetting parameters for an application, but this may give more of a maintenance overhead
d) the subsetting parameters are part of the application. If you have two or more applications being used by a user, you will have to include them in each
e) the subsetting parameters can be included in the user setup ini script run by wsh as well
[DATABASE]
TYPE=ORACLE
[USER]
NAME=NBURROWS
PASSWORD=NBURROWS
ENCRYPTED=FALSE
FULLNAME=NBURROWS
PRIVILEGE=C
[USER]
NAME=CTOMKINSON
PASSWORD=CTOMKINSON
ENCRYPTED=FALSE
FULLNAME=CTOMKINSON
PRIVILEGE=C
[ACL]
APPLICATION=/fusionbci
ROLE=DEFAULT ROLE
USER=NBURROWS
ACCESS=ENABLED
ROLE=DEFAULT ROLE
USER=CTOMKINSON
ACCESS=ENABLED
[SNAPSHOTVAR]
NAME=V_PDA_FBS_SITE_DRIVER
PLATFORM=WIN32
VIRTUALPATH=/fusionbci
USER=NBURROWS
VAR=BI_ID,124547
USER=CTOMKINSON
VAR=BI_ID,119489