PMLiteDB: Streamlining Access Paths for High-Performance Persistent Memory Document Database Systems

Abstract

This paper points out an important challenge for document databases to enjoy the fast byte-addressable persistent memory, such that excessive data indexing and movement become the performance bottlenecks. The advent of byte-addressable persistent memory opens an important opportunity for document databases to read and write durable data fetching them into DRAM. Reaping the benefit of persistent memory is not straightforward, as existing document databases are tailored for disk storage. They assume that the disk and DRAM data movement dominates the performance. However, data indexing becomes the performance bottleneck when porting the document databases to persistent memory. The paper proposes PMLiteDB, the first persistent memory document database with streamlined access paths. PMLiteDB introduces two techniques, direct reading and selective caching. Direct reading streamlines the translation from document IDs to the address of documents whenever possible by swizzling the IDs into persistent memory(PM) references. It guarantees to use only up-to-date PM references when document movements invalidate associated references. Selective caching reduces data movements between DRAM and persistent memory by selectively caching persistent memory data page with DRAM buffer. For accesses on other pages, the mechanism directly load the data on persistent memory. Compared to the design that adopts persistent memory as a fast disk without exploiting the byte-addressability, PMLiteDB achieves 2.33× on average and up to 6.18× speedup.

An Empirical Evaluation of Data Integrity Algorithm Performance in Non-Relational Document Databases

“…When new field is added in the document with new data types it is not necessary to update the entire database structure. These databases provide high data performance for writing and reading which mandatory and requirement for next-generation databases with scalability and flexibility [1].…”