Tag Archives: LevelDB

Streaming full-text search for NodeJS and browsers. Built on LevelDB.


via cshum/levi · GitHub.

Streaming full-text search for Node.js and browsers. Using LevelDB as storage backend.

npm install levi

Full-text search using TF-IDF and cosine similarity. Stream based query mechanism plus query-time field boost options. Provided with configurable text processing pipeline: Tokenizer, Porter Stemmer and Stopwords filter.

Levi is built on LevelUP – a fast, asynchronous, transactional storage interface. By default, it usesLevelDB on Node.js and IndexedDB on browser. Also works with a variety of LevelDOWN compatible backends.

In addition, Levi provides relevancy scoring for live changing data using TF-ICF – a TF-IDF approximation based on existing corpus. Such scoring matches comparably close to TF-IDF when existing corpus is sufficiently large, with significantly better performance O(N) instead of O(N^2).

Event Sourcing using LevelDB and NodeJS


via Event Sourcing using LevelDB and Node.js | Luke Merrett.

We’ve been researching how to peform resilient queue processing at high loads lately with a focus on Akka, the Storm Model and Apache Spark / Storm.  One thing that came up was the use ofLevelDB; a lightweight key / value store supporting asynchronous atomic batch operations.

What interests me is the createReadStream method provided by the LevelUp package for Node.js.  This allows you to iterate over the whole database so may be a suitable candidate for rapid event sourcing.

Why Angular + Meteor?


via Why Angular + Meteor?

There are stacks of stacks. Overflowing. But what makes a great stack? Were it only the name, we’d all be slam dunkin’ with LEBRON (LevelDB, Browserify & Node).