I use an embedded DB for two applications that one of them is Server and another one is client.The client side app. can send fetch data request to server side to retrieve data and show in a table (or sth else).Question is this: How may I save(write) fetched data into pagefile and read that from it when needed(in java, Delphi or c#)?
You can use Shared Memory mechanism. It effectively allocates a chunk of memory in the page file and allows inter-process sharing.
Note: since you specified Delphi and C# tags, I assume you have access to WinAPI functions, such as CreateFileMapping and MapViewOfFile.