List of the Top 2 Key-Value Databases for iPad in 2025

What contributes to the platform independence of eXtremeDB? It features a hybrid data storage approach, allowing for configurations that are entirely in-memory or fully persistent, as well as combinations of both, unlike many other IMDS databases. Additionally, eXtremeDB incorporates its proprietary Active Replication Fabric™, enabling not only bidirectional replication but also multi-tier replication, which can optimize data transfer across various network conditions through built-in compression techniques. Furthermore, it offers flexibility in structuring time series data by supporting both row-based and column-based formats, enhancing CPU cache efficiency. eXtremeDB can operate as either a client/server architecture or as an embedded system, providing adaptable and speedy data management solutions. With its design tailored for resource-limited, mission-critical embedded applications, eXtremeDB is utilized in over 30 million deployments globally, ranging from routers and satellites to trains and stock market operations, showcasing its versatility across diverse industries.

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.