Difference between LDF and MDF | LDF vs. MDF


Difference between LDF and MDF: – If we simply go towards to know the difference between LDF and MDF, then it will be little will confusing for you to understand. I think we should discuss first what is LDF and what is meant by MDF. At least you people would have an idea both have terms have link with database system, which is used to store, analyze and gather information.

Difference between LDF and MDF

Companies use databases to store, analyze, and get valuable information like customers’ requirements, general market trends, accounts, and market styles, inventory of products, employees’ data, and other essential data for their day-to-day businesses. For this purpose, most of the companies use Microsoft SQL for creating directories and storing information, which is what makes it one of the most used program. In the Microsoft SQL database files, MDF and LDF are used.

Both LDF and MDF are data files extensions used by the Microsoft SQL Server files. These file extensions are created automatically whenever a new database is established in the program. Both files are saved in the same location for an easy reference point. But one of the main functions of these files is they are the parts of the backup document (with the document extension .bak) found in the program.

MDF Extension

The file extension .MDF means “Master Database File.” This data file has all the startup information for the databases to perform and monitor all the directories on the SQL server. In addition, it connects to the other documents in the databases. This document is also like an entrance point for storing information and therefore, is vital in admittance and guidance of the content on the server. Just as its name suggests, it controls all of the stored content on the server.

LDF Extension

On the other hand, LDF is the data file extension for the server exchange log for the key data document. It helps one to save the databases information in addition to keeping an archive of all activities and changes made in the information present on the server. So, obviously, it generally consists of the date, time, information on all changes, individual information (regarding who made the changes, i.e. the username). Furthermore, the log also details the computer terminal from where the changes were made and that’s in case if the database is present on a network.

Usually, the .LDF is the associate data file to .MDF, whenever a new directory or a backup file is established. So, the LDF file helps in monitoring unauthorized access or changes to the data. The information, then made available, in the log file can help explain the anomaly. It can also assist in retrieving important and necessary information, and in gaining access to the problem and thus, helps in fixing it.

LDF files prove to be of great importance for many businesses like restoration of individual trades, recovery of recent incomplete transactions at that time when the server started out and recovering the source data file in case a failure occurs. In the situation, where servers face one or more problems, the LDF data file will consider the transactions made during that interval as an incomplete business deal.

For the purpose to deal with a failed SQL server, the LDF document is used to get back to a restoration point created earlier or backup document files in which the databases are fully working. In the case of data source instability, the LDF data files are being used to bring the database files back before the instability occurs.

Finally, we just want to add one more sentence here is that the basic of aim of both LDF and MDF is to make the database more secure and authentic, and whenever due to some reasons, we felt the need of backup files, we should have available there.