With increasing need for faster responses of queries, Teradata Database has come up with many ways to cater to this need. The file segment cache, FSG subsystem, manages database files. It is the memory that is managed by PDE. The Teradata file system, FSYS, uses FSG services to access database segments on disk. AMPs are the basic entity that consumes the FSG cache as part of database segments residing in memory.
Understand FSG cache as a simple cache mechanism that stores parts of data rows in memory so AMPs, when reading data, do not have to go to the physical disk but can read rows from the memory itself. As we know, reading from memory is way faster than from the physical disk.
FSG provides an interface that allows the FSYS logic to merely access and release segments in memory. FSG takes care of the details of getting the data to and from permanent...
