Windows superfetch format -
SuperFetch, is a memory management scheme that enhances the least-recently accessed approach with historical information and proactive memory management. 1
Note that the following format specification are incomplete.
SuperFetch DB files
The Ag*.db files are of the SuperFetch file format. E.g.
AgAppLaunch.db AgCx_SC*.db AgGlFaultHistory.db AgGlFgAppHistory.db AgGlGlobalHistory.db AgGlUAD_%SID%.db AgGlUAD_P_%SID%.db AgRobust.db 
The SuperFetch DB files can be stored in uncompressed or compressed form, where different version of Windows use different compressed forms:
Compressed SuperFetch DB - MEMO file format; Windows Vista
Compressed SuperFetch DB - MEM0 file format; Windows 7
Compressed SuperFetch DB - MAM file format; Windows 8
Compressed SuperFetch DB - MEMO file format
The MEM file consists of:
file header
compressed blocks
This format uses the LZNT1 compression method
The file header is 84 bytes of size and consists of:
Offset Size Value Description 
0	4	"MEMO" (0x4d, 0x45, 0x4d, 0x4f)	Signature	
4	4		Uncompressed (total) data size	
				
Compressed blocks
The compressed block size is the chunk data size, which is part of the LZNT1 compressed data, + 2 bytes for the size of the chunk header itself.
The uncompressed block size is 4096 (0x1000) or the remaining uncompressed data size for the last block.
Compressed SuperFetch DB - MEM0 file format
The MEM file consists of:
file header
compressed blocks
This format uses the LZXPRESS Huffman compression method
The file header is 8 bytes of size and consists of:
Offset Size Value Description 
0	4	"MEM0" (0x4d, 0x45, 0x4d, 0x30)	Signature	
4	4		Uncompressed (total) data size	
				
Compressed blocks
The file header is followed by compressed blocks:
Offset Size Value Description 
0	4		Compressed data size	
4	...		Compressed data	
				
The uncompressed block size is 65536 (0x10000) or the remaining uncompressed data size for the last block.
Compressed SuperFetch DB - MAM file format
The MAM file consists of:
file header
compressed blocks
This format uses the LZXPRESS Huffman compression method.
The file header is 12 bytes of size and consists of:
Offset Size Value Description 
0	4	"MAM\x84" (0x4d, 0x41, 0x4d, 0x84)	Signature	
4	4		Uncompressed (total) data size	
8	4		Unknown (checksum?)	
				
Compressed blocks
The uncompressed block size is 65536 (0x10000) or the remaining uncompressed data size for the last block.
Note the LZXPRESS Huffman variant used differs from the one used in the MEM0 format. This variant can refer to uncompressed data stored in the previous compressed block. The compressed blocks are essentially a single compressed stream.
Uncompressed SuperFetch DB format
TODO
TODO
Offset Size Value Description 
0	4	0x0000000e	Unknown (Database type or signature?)	
4	4		Uncompressed (total) data size	
				
TRX files
The Ag*.db.trx files are of the TRX file format. E.g.
AgCx_SC*.db.trx 
Note that the following format specification is incomplete.
The file header is variable of size and consists of:
Offset Size Value Description 
0	4	1	Unknown (Version?)	
4	4		Unknown	
8	4		File size	
12	4		Maximum number of records (of the record offsets array)	
16	4		Number of records	
20	...		Record offsets array, where the record offset is a 32-bit integer. Unused record offset are set to 0.	
				
Record
TODO describe
See Also
SuperFetch
External Links
Windows SuperFetch file format – partial specification, by ReWolf, October 5, 2011
Windows SuperFetch database format, by the libagdb project, April 2014