MDAC 2.5 SDK - OLE DB Providers
OLE DB Provider for Microsoft Jet


 

File Caching and Data Consistency

Jet was designed as a file-share database. Multiple clients on different machines are able to log in to the database file store and make updates and additions and perform other database operations. This differs from some other, typically client-server, database engines that have a single client (the server) interacting with the file store. Jet uses a file cache to speed access to the database. Because there are multiple clients, it is possible that they can each have file caches that are out of sync with the database file itself. Jet 4.0 exposes the interface IIdle that can be used to flush this cache both of dirty writes (writes waiting in the cache to be flushed to disk) and stale reads (reads that have since been rendered incorrect by changes to that part of the database). Multiuser databases might need to use this in cases where multiple users are making changes to the database at the same time and expecting to see the other updates immediately.