Manage Index

Listing and inspecting the indexes

The FT._LIST command provides a list of all RediSearch indexes in your database:

  1. > FT._LIST
  2. 1) "idx:movie"

FT.INFO provides information about a specific index:

  1. > FT.INFO "idx:movie" 
  3.  1) "index_name"
  4.  2) "idx:movie"
  5.  ...
  6.  5) "index_definition"
  7.  ...
  8.  7) "fields"
  9.  ...
  10. 9) "num_docs"
  11. 10) "4" 
  12. ...

Updating your Indexing

As you build your application and add more information to the database you may need to add new fields to the index. The FT.ALTER command enables you to do this.

  1. > FT.ALTER idx:movie SCHEMA ADD plot TEXT WEIGHT 0.5
  2. "OK"

The WEIGHT declares the importance of this field when calculating result accuracy. This is a multiplication factor (default is 1); so in this example the plot is less important than the title.

Let’s do a query with the new indexed field:

  1. > FT.SEARCH idx:movie "empire @genre:{Action}" RETURN 2 title plot

Dropping the Index

You can drop an index using the FT.DROPINDEX command.

  1. > FT.DROPINDEX idx:movie
  3. "OK"

Dropping an index does not impact the indexed hashes, this means that the movies are still inside the database.

  1. >SCAN 0 MATCH movie:*
  3. 1) "0"
  4. 2) 1) "movie:11002"
  5.    2) "movie:11004"
  6.    3) "movie:11003"
  7.    4) "movie:11005"

Note: You can delete the indexed document/hashes by adding the DD parameter.

Next: Import Sample Dataset