Doubt in DCN

[Former Member]

HI experts,

i have one doubt, For one of our POC i implemented the DCN cache policy for my MBO. As per the DCN cache policy whenever a change in backend table happens we will get the modified data in our CDB. From CDB we can synchronize that to our device. But my doubt is when we are starting an application in our device we should show wome data from backend right. In DCN we cannot achieve that functionality. How we can get that done in this cache policy.

Thanks & Regards

Dinesh.

[Former Member]

Hi Dinesh

When you have an MBO with DCN policy enabled, the same DCN ploicy can also be used to load the CDB. Remember when you load CDB with DCN then the cache never expires. You have to then use DCN also to propagate the changes in EIS via upsert operations to the cache.

Next DCN can also be used in combination with onDeman or OnSchedule, but you have to be careful with partitions you create for that MBO as DCN in a combination mode can not work if the onDemand or OnSchedule policy introduces more than one partition for that MBO.

----------------------- from the sybase doc, read the lines in bold -------------------------------------------------

DCN and Cache refresh policy:

If DCN is the exclusive mechanism for loading and maintaining the data for the MBOs from a cache group, set the cache refresh policy to  DCN.

DCN  with payload directly updates  the CDB by inserting the record into the MBO cache table.

Using a DCN cache group policy ensures that MBO data is updated only through DCN and not another refresh mechanism. When designing your MBOs, keep in mind that if you use other methods (for example, a Scheduled cache group policy), DCNs as well as the scheduled refresh update the MBO. 

If the cache group relies on a combination of DCN with On-demand or Schedule cache refresh policies, then you cannot use DCN with MBOs that define more than one partition (that is, a load operation mapped to synchronization parameters in Unwired WorkSpace). The cache refresh policy does  not support updating data inserted via DCN when the configured cache policy triggers a refresh of the partitioned data.

If the load operation initializes the MBO, and you use DCN to maintain the MBO, then associate the MBO with a cache group that implements an infinite schedule. Do not send DCN messages until the cache is initialized.

And the link:

http://infocenter.sybase.com/help/index.jsp?topic=/com.sybase.infocenter.dc01781.0212/doc/html/fre12...

Regards

LNV