---
title: Indexing Text Arrays
description: Add text arrays to the index
canonical: https://docs.paradedb.com/documentation/indexing/indexing-arrays
---

The BM25 index accepts arrays of type `text[]` or `varchar[]`.

```sql
CREATE TABLE array_demo (id SERIAL PRIMARY KEY, categories TEXT[]);
INSERT INTO array_demo (categories) VALUES
    ('{"food","groceries and produce"}'),
    ('{"electronics","computers"}'),
    ('{"books","fiction","mystery"}');
```

<CodeGroup>
```sql SQL
CREATE INDEX search_idx ON array_demo
USING bm25 (id, categories)
WITH (key_field = 'id');
```

```python Django
from django.db import connection
from paradedb.indexes import BM25Index

with connection.schema_editor() as schema_editor:
    schema_editor.add_index(
        ArrayDemo,
        BM25Index(
            fields={
                "id": {},
                "categories": {},
            },
            key_field="id",
            name="search_idx",
        ),
    )
```

```python SQLAlchemy
from sqlalchemy import Index
from paradedb.sqlalchemy import indexing

idx = Index(
    "search_idx",
    indexing.BM25Field(ArrayDemo.id),
    indexing.BM25Field(ArrayDemo.categories),
    postgresql_using="bm25",
    postgresql_with={"key_field": "id"},
)

with engine.begin() as conn:
    idx.create(conn)
```

```ruby Rails
ActiveRecord::Base.connection.add_bm25_index(
  :array_demo,
  fields: {
    id: {},
    categories: {}
  },
  key_field: :id,
  name: :search_idx
)
```

</CodeGroup>

Under the hood, each element in the array is indexed as a separate entry. This means that an array is considered a
match if **any** of its entries is a match.

```sql
SELECT * FROM array_demo WHERE categories === 'food';
```

```ini Expected Response
 id |           categories
----+--------------------------------
  1 | {food,"groceries and produce"}
(1 row)
```

Text arrays can be [tokenized](/documentation/tokenizers/overview) and [filtered](/documentation/token-filters/overview) in the same way as text fields:

<CodeGroup>
```sql SQL
CREATE INDEX search_idx ON array_demo
USING bm25 (id, (categories::pdb.literal))
WITH (key_field = 'id');
```

```python Django
from django.db import connection
from paradedb.indexes import BM25Index

with connection.schema_editor() as schema_editor:
    schema_editor.add_index(
        ArrayDemo,
        BM25Index(
            fields={
                "id": {},
                "categories": {"tokenizer": "literal"},
            },
            key_field="id",
            name="search_idx",
        ),
    )
```

```python SQLAlchemy
from sqlalchemy import Index
from paradedb.sqlalchemy import indexing

idx = Index(
    "search_idx",
    indexing.BM25Field(ArrayDemo.id),
    indexing.BM25Field(
        ArrayDemo.categories,
        tokenizer=indexing.tokenize.literal(),
    ),
    postgresql_using="bm25",
    postgresql_with={"key_field": "id"},
)

with engine.begin() as conn:
    idx.create(conn)
```

```ruby Rails
ActiveRecord::Base.connection.add_bm25_index(
  :array_demo,
  fields: {
    id: {},
    categories: { tokenizer: :literal }
  },
  key_field: :id,
  name: :search_idx
)
```

</CodeGroup>