LevelDB is not A SQL Database

LevelDB stores keys, values, and arbitrary byte arrays. Data is sorted by key. It supports batching, forward and reverse iteration, and compression of data via Google's Snappy compression tool.

LevelDB is not a SQL database. It doesn't support SQL queries, which is different from other NoSQL or dbm stores. It does not support indexes. LevelDB is used by applications as a library. It does not offer a command-line interface or a server.

MariaDB 10.0 includes a storage engine that lets users access LevelDB tables directly from MariaDB. [6]

LevelDB is based on concepts that Google developed for its Bigtable data base system. The table implementation for the Bigtable system was created in about 2004 and is based on an entirely different Google internal code base than the LevelDB code. This code base is dependent on a number Google code libraries that aren't open source. Therefore, it would be difficult to open source the code. Jeff Dean and Sanjay Ghemawat wanted to develop an application that resembled the Bigtable tablet stack, but with only a few dependencies, and was suitable for open source, and also suitable for use with Chrome for the IndexedDB implementation. LevelDB was written by them in the beginning of 2011 with similar design to the Bigtable tablet stack but without sharing any of their code. [7]

Usage[edit]

LevelDB is used as the backend database for Google Chrome's IndexedDB and is one of the backends that are supported for Riak. [88 Bitcoin Core and go–ethereum also store blockchain metadata using a LevelDB Database. 9. Minecraft Bedrock Edition uses a modified version to store chunks and entity data storage. Autodesk AutoCAD 2016 also uses LevelDB.

Performance[edit]

Google has provided benchmarks that evaluate the performance of LevelDB against SQLite or Kyoto Cabinet in different scenarios. 11 LevelDB is superior to both SQLite & Kyoto Cabinet in sequential-order read and write operations. LevelDB excels at batch writing however it is slower than SQLite when it comes to large values. minecraft After SQLite configuration issues were discovered in the previous version, the current benchmarks were updated. The updated benchmarks[13reveal that LevelDB also outperforms Berkeley DB however these tests also show that OpenLDAP LightningDB is significantly faster (~10 times in certain scenarios) in read operations, and certain types of writing (e.g. batch and synchronous write, see the link above) and is also nearly equal in the rest of the tests.

Please note that the benchmarks above are from the year 2011 through 2014. They may not be historical in any way. SQLite, for example has significantly improved its efficiency. [14]

Bugs and reliability [edit]

LevelDB has been known to have database corruption bugs. [15][16][17][18][19][20] A study from 2014 has found that, on older (non-checksummed) file systems, the database could become corrupted after a crash or power failure. [21]

Lightning Memory-Mapped Database rocksDB a free and open-source software portal


References[edit]

^ "Release 1.23". 23 February 2021. Retrieved 13 March 2021. "Google Research Scientists and Engineers": Jeffrey Dean. Google, Inc. ^ "Research Scientists and Engineers: Sanjay Ghemawat". Google, Inc. ^ "Google Open-Sources NoSQL Database Called LevelDB". ReadWriteWeb. July 30 2011. The original article was removed on August 16 the 16th of August, 2011. Retrieved July 30, 2011. ^ "Google Open Source Blog: LevelDB: A Fast Persistent Key-Value Store". Google, Inc. ^ LevelDB storage engine ^ Jeff Dean. "LevelDB mailing list: Current Status of LevelDB" ^ LevelDB. Docs.basho.com. Retrieved on 2013-09-18. ^ Andreas M. Antonopoulos. "Chapter 7. The Blockchain Retrieved 8 January 2015. ^ "Bedrock Edition level format". ^ "LevelDB Benchmarks". Google, Inc. Retrieved from the original on 2011-08-20. ^ "LevelDB Benchmark discussion". Database Microbenchmarks Retrieved 2014-08-09 from the Wayback Machine, Symas Corp. 2012-09. Retrieved 22 October 2016 "Measuring and Reducing CPU Usage in SQLite". Repairing LevelDB Problems Google/leveldb GitHub Unrecoverable Chromium corruption and corruption following power loss. The problem is that it's corrupted in Ethereum All File System Are Not Equal: The Complexity of Crafting Crash Consistent Applications 2014. pp. 433-448. ISBN 9781931971164. External links[edit]

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