Slow Sync

The slow sync is similar to two-way sync, except that all the items in the client databases are compared with all the items in the server databases, on a field-by-field basis. A slow sync can be requested if the client and server data is mismatched or if the client or server loses its information.

Typically, the very first sync that a client performs is a slow sync. After that, the client performs fast syncs. If the data on the server or client is lost or corrupted, the next sync must be a slow sync.

In practice, a slow sync means that the client sends all its data to the server and the server does a field-by-field analysis, comparing its own data with that sent by the client. After the analysis, the server returns all the modification information to the client. In turn, the client returns the mapping information for all data items added by the server. Figure 1–6 illustrates this process.

Figure 1–6 Slow Sync