Microsoft Jet databases are managed by  ESENT or ESE. When you place a Jet database on a compressed drive, you may experience write-through delays, which can cause database corruption.

Jet database and related files include DIT files, logs, checkpoints and temporary databases:

Active Directory (<b>NTDS</b>)
File Replication service (<b>FRS</b>)
Windows Internet Name service (<b>WINS</b>)
Security Configuration Engine (<b>SCE</b>)
Certificate Server
Terminal Services Session folder
Terminal Services Licensing service
Catalog database
Help and Support Services
Directory Synchronization service (<b>MSDSS</b>)
Remote Storage (<b>RSS</b>)
Phone Book service
Single Instance Store (<b>SIS</b>) Groveler
Windows NT Backup/Restore
Exchange store
Microsoft Exchange folder (<b>SRS</b> and <b>DXA</b>)
Key Management service (<b>KMS</b>)
Instant Messaging
Content Indexing