> ## Documentation Index
> Fetch the complete documentation index at: https://paradedb-ankitml-legacy-docs-remove.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Ngram

> Splits text into small chunks called grams, useful for partial matching

The ngram tokenizer splits text into "grams," where each "gram" is of a certain length.

The tokenizer takes two arguments. The first is the minimum character length of a "gram," and the second is the maximum character length. Grams will be generated for all sizes between
the minimum and maximum gram size, inclusive. For example, `pdb.ngram(2,5)` will generate tokens of size `2`, `3`, `4`, and `5`.

To generate grams of a single fixed length, set the minimum and maximum gram size equal to each other.

```sql theme={null}
CREATE INDEX search_idx ON mock_items
USING bm25 (id, (description::pdb.ngram(3,3)))
WITH (key_field='id');
```

To get a feel for this tokenizer, run the following command and replace the text with your own:

```sql theme={null}
SELECT 'Tokenize me!'::pdb.ngram(3,3)::text[];
```

```ini Expected Response theme={null}
                      text
-------------------------------------------------
 {tok,oke,ken,eni,niz,ize,"ze ","e m"," me",me!}
(1 row)
```

## Ngram Prefix Only

The generate ngram tokens for only the first `n` characters in the text, set `prefix_only` to `true`.

```sql theme={null}
SELECT 'Tokenize me!'::pdb.ngram(3,3,'prefix_only=true')::text[];
```

```ini Expected Response theme={null}
 text
-------
 {tok}
(1 row)
```