Data subsetting depending on connected user

Question

hi there.
It is possible to define parameters in the where clause when defining a publication item. This parameter is resolved at runtime which provides the possiblity to send just a subset of the data of the given publication item back to the remote client.
In my case the subset is driven by the connected user. How can I configure this requirement. Do I need to define a own MyCompose class or even an own queue for this purpose?
thx for any hints.
j.

Answer 1

Here is a section on shared maps from the documentation. You accomplish your task by assigning the user to a group.
It is very common for publications to contain publication items that are used specifically for lookup purposes. That is, a publication item that creates a read-only snapshot. The server may change these snapshots, but the client would never update them directly. Furthermore, many users often share the data in this type of snapshot. For example, there could be a publication item called zip_codes, which is subscribed to by all Mobile users.
The main function of Shared Maps is to improve scalability for this type of publication item by allowing users to share record state information and reduce the size of the resulting replication map tables. By default, if you have a non-updatable publication item, it defaults to using shared maps.
Note:
Shared Maps can also be used with updatable snapshots if the developer is willing to implement their own conflict detection and resolution logic; however, normally shared maps are only for non-updatable snapshots.
Shared maps shrink the size of map tables for large lookup publication items and reduce the MGP compose time. Lookup publication items contain read-only data that is not updatable on the clients and that is shared by multiple subscribed clients. When multiple users share the same data, their query subsetting parameters are usually identical.
For example, a query could be the following:
SELECT * FROM WHERE EMP WHERE DEPTNO = :dept_id
In the preceding example, all users that share data from the same department have the same value for dept_id. The default sharing method is based on subscription parameter values.
In the following example, the query is:
SELECT * FROM WHERE EMP WHERE DEPTNO = ( SELECT DEPTNO FROM EMP WHERE EMPNO = :emp_id )
In this example, users from the same departments still share data. Their subsetting parameters are not equal, because each user has a unique emp_id. To support the sharing of data for these types of queries (as illustrated by the example), a grouping function can be specified. The grouping function returns a unique group id based on the client id.
There is also another possible use for shared maps. It is possible to use shared maps for shared updatable publication items. However, this type of usage requires implementation of a custom dml procedure that handles conflict resolution.