There are 3 file types use the .LDB file extension:
1. Microsoft Access Lock File
An LDB file is a lock information file that prevents an Access database from being changed by more than one user at a time. It also helps ensure updates will not be unexpectedly overwritten. LDB files are created and deleted automatically by Access when a database is opened and closed.
LDB files are not meant to be opened by the user, they are only meant for locking information in an .MDB Access database. By locking the information in the database, multiple users are not allowed to overwrite each other's updates.
NOTE: LDB files have the same name as the opened database (the .MDB file) and is located in the same folder.
Updated: August 30, 2017
2. Minecraft Level File
An LDB file contains a level used by the Windows 10, Android, and iOS versions of Minecraft, a popular Minecraft block-building game. It stores information about a playable level, or world, in key value format, which is based on the LevelDB format developed by Google. LDB files are compressed with Zlib compression.
LDB files are often associated with "Minecraft: Pocket Edition" and "Bedrock Engine" because the LDB format was introduced in Minecraft: Pocket Edition (the name of the first mobile versions of Minecraft) which is also when the game first used the Bedrock Engine. However, the "Pocket Edition" name was eventually dropped with the release of the "Better Together Update" on September 20, 2017. Pocket Edition versions are now simply called "Minecraft."
In Windows 10, Android, and iOS, LDB files are located in the /db path of a level folder in the game installation directory. LDB files are often located with .DAT and .LOG files.
Updated: June 16, 2018
3. Max Payne Level File
Contains level data for Max Payne and Max Payne 2: The Fall of Max Payne; can be created or edited using MaxEd, the official Max Payne level editor, which is part of the Max-FX toolset.
Updated: September 9, 2007