If the Dekho database is being housed within a shared infrastructure, response times may degrade when other databases are being heavily hit by separate applications (e.g. asset management systems).
The usage of specific databases can be monitored using a performance counter to see if symptoms of slow performance in Dekho can be correlated with large numbers of transactions per second in other databases.
In the first instance, it is recommended to work with your Database Administrator to see if performance can be improved at the database tier by re-allocating resource priorities for the various databases.
As with latency, a workaround would be to install a database instance local to the Dekho application which voids any competing external systems. However, the Dekho instance will be competing against ArcGIS for Server and Dekho for resources, so the server needs sufficient capacity to support this total load and each application tuned accordingly.