SOLIDWORKS PDM uses a database server and an archive server for hosting central data about files and activities in a SOLIDWORKS PDM vault.
When a client connects to a SOLIDWORKS PDM vault through the vault view and browses for files, views file data cards, searches for files, and so on, the information is sent between the client and the database server. When a client retrieves physical files stored in a vault (such as drawings and documents) from the archive to the local vault view (cache) by using functions such as Get or Check out, the files are retrieved from the archive server and sent to the client. The time it takes to transfer these files depends on the size and speed of the network.
In a LAN environment, the files are normally transferred quickly since the archive server resides locally to the clients. If the SOLIDWORKS PDM vault is shared between multiple offices over a WAN connection, the performance will decrease and relies heavily on the speed of the connection. Both the information from the database server (which is speedy since only small text data is sent) and the physical files (which can take anywhere from seconds to hours depending on file size) are transferred over the WAN.
By using the vault replication feature in SOLIDWORKS PDM, you can balance the amount of data that is transferred over a slow WAN connection by setting up a local archive servers in each office, hosting a replicated copy of the vault archive. When clients in each office work in the vault, the information is still sent from the central database server, but the physical files are now retrieved from the closest archive server hosting a copy of the archived file.
If the file archive has already been replicated, the file will be retrieved from the local archive server in the WAN office. If the file has been added to an archive server in another office and has not yet been replicated to the local archive server, the file archive will be automatically replicated when the file is initially retrieved by a client so that the archived file is accessible on the local archive server to all other clients in the same office.