issue_comments: 1105615625

The datasette-geojson plugin is actually an interesting case here, because of the way it converts SpatiaLite geometries into GeoJSON: https://github.com/eyeseast/datasette-geojson/blob/602c4477dc7ddadb1c0a156cbcd2ef6688a5921d/datasette_geojson/init.py#L61-L66

```python

if isinstance(geometry, bytes):
    results = await db.execute(
        "SELECT AsGeoJSON(:geometry)", {"geometry": geometry}
    )
    return geojson.loads(results.single_value())

`` That actually seems to work really well as-is, but it does worry me a bit that it ends up having to execute an extraSELECT` query for every single returned row - especially in streaming mode where it might be asked to return 1m rows at once.

My PostgreSQL/MySQL engineering brain says that this would be better handled by doing a chunk of these (maybe 100) at once, to avoid the per-query-overhead - but with SQLite that might not be necessary.

At any rate, this is one of the reasons I'm interested in "iterate over this sequence of chunks of 100 rows at a time" as a potential option here.

Of course, a better solution would be for datasette-geojson to have a way to influence the SQL query before it is executed, adding a AsGeoJSON(geometry) clause to it - so that's something I'm open to as well.