DB2 Replication Guide and Reference
Mobile replication requirements center around having copies of centrally
located tables on mobile clients. Special considerations arise with
this approach, primarily from the need for the target site to initiate and
control the replication operation. IBM Replication supports mobile
replication requirements in the following ways:
- On-demand execution of the Capture and Apply programs - In an
unpredictable mobile environment, the mobile client must initiate and control
the connections. To reduce communication costs, the duration of phone
connections must be minimized and the mobile client is not continuously in
operation. The Capture and Apply programs must operate only for the
duration within which all the accumulated transactions are captured and copied
to or from the centrally located tables. When the replication sources
and subscriptions are defined on the mobile client, the Capture and Apply
programs are independent of all other IBM Replication components. They
can be run in an on-demand mode whenever required to dynamically connect to
the target site.
- Push and pull options - If you must upload new or changed data
from the mobile clients to the replication source site, the Apply program on
the mobile client automatically pushes the data to the replication source
site.
- Changed data retention - Because of unpredictable connection
arrangements, you must ensure that all changed data is retained until each of
the mobile clients has replicated its data. The best way to configure
IBM Replication for optimized data retention is to use a CCD table, and
possibly locate it on a staging server. Two Apply programs are
needed. One Apply program moves the data from the CD and UOW tables to
a CCD table so that the Capture program can prune the changed data on a
regular basis. Another Apply program, on an intermediate server, moves
the data from the CCD table to the mobile client. This configuration is
not available for update-anywhere replication.
[ Top of Page | Previous Page | Next Page | Table of Contents | Index ]
[ DB2 List of Books |
Search the DB2 Books ]