# Running queries from Builder
Once you have created your Postgres connection in the CARTO Workspace (see [*Getting Access*](https://docs.carto.com/data-and-analysis/analytics-toolbox-for-postgresql/overview/getting-started) for details), you can create custom SQL layers in Builder that make use of the Analytics Toolbox for Postgres.
To get started, let’s run a simple example query to subdivide the area into Quadbin grid cells using the [`QUADBIN_POLYFILL`](https://docs.carto.com/data-and-analysis/analytics-toolbox-for-postgresql/sql-reference/quadbin#quadbin_polyfill) function from the *quadbin* module.
1. Click on the *Add source from* button in Builder, that can be found at the bottom left of the screen.
2. Select the second tab *Custom Query (SQL)* and pick the Postgres connection that you will use to run the query. Please make sure this connection has access to the Analytics Toolbox database.
3. Click on *Add source*. A SQL console will be displayed.
4. Copy and paste the following query:
```sql
WITH data AS(
select 'New York' as city, ST_POINT(-74.00597, 40.71427) as geom
union all select 'Boston', ST_POINT(-71.05977, 42.35843)
union all select 'Philadelphia',ST_POINT(-75.16379, 39.95233)
union all select 'Washington',ST_POINT(-77.03637, 38.89511)
)
SELECT carto.QUADBIN_FROMGEOGPOINT((geom),9) as quadbin from data
```
You can also take advantage of the function directly from a table from your database and combine it with other functions, such as the `QUADBIN_BOUNDARY` function, to get the geography boundary for a given quadbin:
```sql
WITH data as (SELECT geom
FROM mydatabase.myschema.table),
quadbins as (
SELECT carto.QUADBIN_POLYFILL(geom
, 14) quadbins_polyfill from data
)
SELECT carto.QUADBIN_BOUNDARY(unnest(quadbins_polyfill)) as geom from quadbins
```
5. Run the first query. In this example we will showcase how to get the quadbin representationat at resolution level 9 for the geographic coordinates of four US cities dusing the `QUADBIN_POLYFILL` function.
{% hint style="info" %}
Try executing any of the queries included in every function definition in the [SQL Reference](https://docs.carto.com/data-and-analysis/analytics-toolbox-for-postgresql/sql-reference).
{% endhint %}
