What is LevelDB?
LevelDB, a high-performance key-value storage library created by Google, is engineered to maintain an ordered association between string keys and string values. It treats both keys and values as arbitrary byte arrays, with the data organized in a sorted manner according to the keys. Users can implement a custom comparison function to alter the default sorting dynamics if desired. The library supports batching of multiple changes into a single atomic operation, which helps preserve data integrity during updates. Moreover, it enables the creation of temporary snapshots, allowing users to capture a consistent view of the data at any point in time. Users can also iterate through the stored data in both forward and backward directions, which enhances the flexibility of data access. To improve storage efficiency, data is automatically compressed using the Snappy compression algorithm. Furthermore, the library interacts with the operating system through a virtual interface, giving users the option to customize interactions with external environments, including file system operations. In practical usage, for instance, a database may contain one million entries, each entry comprising a 16-byte key paired with a 100-byte value. Interestingly, during benchmarking, the values compress to about half their original size, resulting in considerable space savings. We provide thorough performance metrics for sequential reads in both directions and evaluate the effectiveness of random lookups to highlight the library's capabilities. This extensive performance evaluation assists developers in identifying ways to optimize their utilization of LevelDB in diverse applications, ensuring they can maximize the benefits offered by this powerful library. Additionally, understanding these metrics can lead to improved design choices in database implementation and usage.