White Papers

RediSearch: A High Performance Search Engine as a Redis Module

RediSearch is a full-text search engine developed from scratch on top of Redis, using the new Redis Modules API to extend Redis with new commands and capabilities. Its main features include:

  • Simple, fast indexing and searching
  • Data stored in RAM, using memory-efficient custom data structures
  • Support for multiple languages using utf-8 encoding
  • Document and field scoring
  • Numeric filtering of results
  • Query expansion by Stemming
  • Exact phrase search
  • Filtering results by specific properties (e.g. search “foo” in title only)
  • Powerful auto-suggest engine
  • Incremental indexing (without the need to optimize or vacuum the index)
  • Support for use as a search index for documents stored in another database
  • Support for indexing of existing HASH objects already in redis as documents
  • Scaling to multiple Redis instances

In this paper, we’ll discuss the internal design and features of RediSearch and demonstrate its current capabilities.