---
title: Aggregate Syntax
description: Accelerate aggregates with the ParadeDB index
canonical: https://docs.paradedb.com/documentation/aggregates/overview
---

The `pdb.agg` function accepts an Elasticsearch-compatible JSON aggregate query string. It executes the aggregate using the
[columnar](/welcome/architecture#columnar-index) portion of the ParadeDB index, which can significantly accelerate performance compared to vanilla Postgres.

For example, the following query counts the total number of results for a search query.

```sql
SELECT pdb.agg('{"value_count": {"field": "id"}}')
FROM mock_items
WHERE category === 'electronics';
```

```ini Expected Response
      agg
----------------
 {"value": 5.0}
(1 row)
```

This query counts the number of results for every distinct group:

```sql
SELECT rating, pdb.agg('{"value_count": {"field": "id"}}')
FROM mock_items
WHERE category === 'electronics'
GROUP BY rating
ORDER BY rating
LIMIT 5;
```

```ini Expected Response
 rating |      agg
--------+----------------
      3 | {"value": 1.0}
      4 | {"value": 3.0}
      5 | {"value": 1.0}
(3 rows)
```

## Multiple Aggregations

To compute multiple aggregations at once, simply include multiple `pdb.agg` functions in the target list:

```sql
SELECT
  pdb.agg('{"avg": {"field": "rating"}}') AS avg_rating,
  pdb.agg('{"value_count": {"field": "id"}}') AS count
FROM mock_items
WHERE category === 'electronics';
```

```ini Expected Response
   avg_rating   |     count
----------------+----------------
 {"value": 4.0} | {"value": 5.0}
(1 row)
```

## JSON Fields

If `metadata` is a JSON field with key `color`, use `metadata.color` as the field name:

```sql
SELECT pdb.agg('{"terms": {"field": "metadata.color"}}')
FROM mock_items
WHERE id @@@ pdb.all();
```

<Note>
If a text or JSON field is used inside `pdb.agg`, it must use the [literal](/documentation/tokenizers/available-tokenizers/literal) tokenizer.
</Note>