A contacts database will be compressed automatically by the server based on two compression thresholds.
These thresholds are expressed in terms of the total number of Create, Update or Delete (CUD) operations performed on a contacts database since the last time the database was compressed.
The first threshold is 16 CUD operations. Once this threshold is reached the server will request an “idle” compression. This type of compression will only result in a compression request (internal to the server) if there are no operations of higher priority carried out by the server within 1 second.
The second threshold is 64 CUD operations. Once this threshold is reached the server will request an “immediate” compression. This type of compression will always result in a compression request.
Clients should still request database compression since short sessions with a database may not allow either of the CUD operation thresholds to be reached.
There is no requirement to request compression during “bulk” operations (more than 64 CUD operations) but it is recommended to request a compression after any series of CUD operations, to ensure minimum fragmentation of the database.