The Art of SQL Server FILESTREAM - Red Gate Software

Chapter 9: Investigating FILESTREAM Databasessys.system_internals_partitionsThis is another internal view that contains some FILESTREAM-related information. Twocolumns that are relevant to the FILESTREAM feature are filestream_filegroup_idand filestream_guid. filestream_filegroup_id refers to the filegroup ID of theFILESTREAM filegroup.Again, Books Online warns that this view is reserved for the internal system usageonly and future compatibility is not guaranteed. Personally, however, I found this viewvery helpful and have used it a number of times to retrieve various pieces of informationrelated to the location of the FILESTREAM folders (see, for example, Listings 9-10and 9-11).sys.filestream_tombstone_*This is an internal table that the FILESTREAM feature uses to keep track of the garbagefiles. When a garbage file is generated, it is recorded in this table and the garbage collectorreads information from the tombstone table and cleans the garbage based on it.A detailed explanation of this table is provided in Chapter 7.Useful FILESTREAM Metadata QueriesWhile working with FILESTREAM-enabled databases, you might very often come acrosscases where you need to query the FILESTREAM metadata to retrieve information. Thissection provides some FILESTREAM metadata queries, using many of the system catalogviews discussed previously, which you might find very helpful.335