Starcounter persists user data on the disk in the form of transaction log files. This ensures data durability and allows to reload data on database restart. The disk can contain many log files. Each transaction log file is 256Mb in size. Starcounter writes transaction data to the current log file until it is full and then creates and switches to a new one. The format of transaction log files aims mainly to allow high throughput of transaction data rather than to save disk space or to reload the database quickly. To overcome it, optimized log files are introduced. Optimized log files are created in the background. It combines data from any number of transaction log files and stores it in a compact and read efficient format. Effectively, it’s the image of the database at a specific point of time. To reload database using a optimized log, Starcounter needs an optimized log file and all transaction log files that comes after it. Should more than one optimized log file exists on disk, Starcounter performs a database reload using the most recent one. Thus, all optimized log files except the most recent one are no longer required for database reload. As well as all transaction log files that were compacted. But they may be necessary for other tasks, such as data replication.