Introduction to RediSearch

RediSearch is a powerful search and indexing engine built as a Redis Module. It provides highly efficient full-text search, secondary indexing, and querying capabilities to Redis, making it an indispensable tool for developers looking to enhance their Redis capabilities.

Key Features of RediSearch

• Full-text search with advanced querying capabilities
• Secondary indexing and querying of multiple data types
• Optimized for performance with minimal overhead

Basic APIs and Code Snippets

Create an Index

  FT.CREATE myIndex ON HASH PREFIX 1 doc:
  SCHEMA title TEXT WEIGHT 5.0 body TEXT url TEXT

Index a Document

  HSET doc:1 title "Redisearch Introduction" body "Learn how to use Redisearch for full-text search capabilities" url "https://example.com/docs/redisearch"

Search the Index

  FT.SEARCH myIndex "Redisearch" 

Delete an Index

  FT.DROPINDEX myIndex

Advanced API Examples

Creating a Complex Schema

  FT.CREATE myIndex ON HASH PREFIX 1 doc:
  SCHEMA title TEXT WEIGHT 5.0 body TEXT url TAG SORTABLE

Performing a Fuzzy Search

  FT.SEARCH myIndex "Red~"

Using Numeric Filters

  FT.SEARCH myIndex "@price:[100 200]"

Tag Field Search

  FT.SEARCH myIndex "@url:{http://example.com}"

Building a Simple Application with RediSearch

Let’s build a sample application to demonstrate the use of the APIs mentioned above.

Application Setup

  import redis
  from redis.commands.search.field import TextField, NumericField, TagField
  from redis.commands.search.indexDefinition import IndexDefinition
  from redis.commands.search.client import SearchIndex

  client = redis.StrictRedis()

  # Create Index Definition
  schema = [
    TextField("title", weight=5.0),
    TextField("body"),
    TagField("url", sortable=True)
  ]
  definition = IndexDefinition(prefix=["doc:"])

  # Create Index
  idx = SearchIndex(client, "myIndex")
  idx.create_index(fields=schema, definition=definition)

  # Adding a document
  client.hset("doc:1", mapping={
    "title": "Redisearch Introduction",
    "body": "Learn how to use Redisearch for full-text search capabilities",
    "url": "https://example.com/docs/redisearch"
  })

  # Perform a search
  res = idx.search("Redisearch")
  for doc in res.docs:
    print(f"Document {doc.id}: {doc.title}")

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