MDF Viewer Resources for SQL Server Files
MDF Viewer resources explain SQL Server database files, point you to official Microsoft guides and link every SysTools tool built for MDF problems.
MDF File
Primary data file. Every database has one, and it points to the other files.
NDF File
Secondary data file. Optional, and it spreads data across more disks.
LDF File
Transaction log file. SQL Server uses it to recover the database.
Official Microsoft Guides for MDF Problems
Database Files and Filegroups
Microsoft explains primary, secondary and log files and the file extensions SQL Server recommends.
Detach and Attach a Database
Microsoft lists the attach rules, including the block on attaching a newer database to an earlier SQL Server version.
MSSQLSERVER_5120 Error
Microsoft lists the causes of error 5120 and the permission checks for the SQL Server service account.
Every MDF Viewer Tool in One Place
Free SQL MDF Recovery
Handles corrupt or suspect MDF files that SQL Server will not attach.
Open Tool →Free SQL Backup Recovery
Reaches into backup files that fail to restore.
Open Tool →Free SQL MDF Password Recovery
Resets lost SA and user passwords stored in master.mdf.
Open Tool →Free SQL LDF Viewer
Shows the activity logged in a transaction log file.
Open Tool →Free SQL Decryptor
Removes encryption from procedures, views, functions and triggers.
Open Tool →Free SQL Server Database Restore Manager
Puts MDF, NDF and master databases back in service.
Open Tool →Help, Company and Legal Pages
Help and Company
Questions About SQL Server Database Files
Does every SQL Server database have an MDF file?
Yes. Every database has one primary data file, and Microsoft recommends the .mdf extension for it. That file points to the other files in the database.
What is the difference between MDF and NDF files?
NDF files are optional secondary data files that spread database data across more disks. You add them to MDF Viewer next to the MDF file before your first scan.
Which tool opens LDF files?
Free SQL LDF Viewer opens transaction log files. MDF Viewer scans the MDF and NDF data files.
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