Schema definition
How to define the schema of an index.
An index structure is defined by a schema. The schema specifies the fields, their types, whether they should be indexed or stored, and other additional configuration options. By properly configuring the schema, you can optimize search performance and control the storage requirements of your index.
FT.CREATE idx
ON HASH
PREFIX 1 blog:post:
SCHEMA
title TEXT WEIGHT 5.0
content TEXT
author TAG
created_date NUMERIC SORTABLE
views NUMERIC
In this example, a schema is defined for an index named idx
that will index all hash documents whose keyname starts with blog:post:
.
The schema includes the fields title
, content
, author
, created_date
, and views
. The TEXT
type indicates that the title
and content
fields are text-based, the TAG
type is used for the author
field, and the NUMERIC
type is used for the created_date
and views
fields. Additionally, a weight of 5.0 is assigned to the title
field to give it more relevance in search results, and created_date
is marked as SORTABLE
to enable sorting based on this field.
You can learn more about the available field types and options on the FT.CREATE
page.
More schema definition examples
Index tags with a separator
Index books that have a categories
attribute, where each category is separated by a ;
character.
FT.CREATE books-idx
ON HASH
PREFIX 1 book:details
SCHEMA
title TEXT
categories TAG SEPARATOR ";"
Index a single field in multiple ways
Index the sku
attribute from a hash as both a TAG
and as TEXT
:
FT.CREATE idx
ON HASH
PREFIX 1 blog:post:
SCHEMA
sku AS sku_text TEXT
sku AS sku_tag TAG SORTABLE
Index documents with multiple prefixes
Index two different hashes, one containing author data and one containing book data:
FT.CREATE author-books-idx
ON HASH
PREFIX 2 author:details: book:details:
SCHEMA
author_id TAG SORTABLE
author_ids TAG
title TEXT name TEXT
In this example, keys for author data use the key pattern author:details:<id>
, while keys for book data use the pattern book:details:<id>
.
Only index documents if a field specifies a certain value using FILTER
Index authors whose names start with G:
FT.CREATE g-authors-idx
ON HASH
PREFIX 1 author:details
FILTER 'startswith(@name, "G")'
SCHEMA
name TEXT
Index only books that have a subtitle:
FT.CREATE subtitled-books-idx
ON HASH
PREFIX 1 book:details
FILTER '@subtitle != ""'
SCHEMA
title TEXT
Index a JSON document using a JSONPath expression
Index a JSON document that has title
and categories
fields. The title
field is indexed as TEXT
and the categories
field is indexed as TAG
.
FT.CREATE idx
ON JSON
SCHEMA
$.title AS title TEXT
$.categories AS categories TAG
You can learn more about the available field types and options on the FT.CREATE
page.