🏡 Home 👈 Prev 👉 Next

⚡  ElasticsearchBook.com is crafted by Jozef Sorocin and powered by:

• Spatialized.io (Elasticsearch & Google Maps consulting)
• in cooperation with Garages-Near-Me.com (Effortless long-term parking across Germany)

What's What

Geographical objects and shapes are supported in ES through these field types:

1. GEO POINTS → latitude/longitude pairs or geo hashes. Primarily used for:
   • finding locations within a bounding box, within a certain distance of a central point, within a polygon, or within a geo_shape query,
   • aggregating locations geographically or by distance from a central point,
   • integrating distance into a document’s relevance score,
   • and sorting documents by distance.
2. GEO SHAPES → select GeoJSON and WKT entities. Used for:
   • filtering geo_shape documents using the spatial relations INTERSECTS, DISJOINT, WITHIN, or CONTAINS
3. SHAPES → arbitrary x, y cartesian shapes Only available within X-Pack — a closed-source collection of features that's part of an official Elasticsearch Subscription.

<aside> ⚠️ The third dimension (z-value) in any of the above field types is also accepted but only the latitude and longitude values will be indexed — the third dimension is ignored!

</aside>

Coordinate Accuracy & Precision

People often ask how many coordinate decimal places they should store.

Let's clarify that by borrowing from this GIS Stack Exchange thread and this answer by whuber:

• Accuracy is the tendency of your measurements to agree with the true values.
• Precision is the degree to which your measurements pin down an actual value.

I'm not going to get into the accuracy part and will rather focus on precision — here's a summary of what each digit in a decimal degree signifies:

• The sign tells us whether we are north or south, east or west on the globe (+ N/E, - S/W).
• A nonzero hundreds digit tells us we're using longitude, not latitude! See below — the x-axis represents the longitude, the y-axis the latitude:

                               North (+90)
                                    |
                                    |
                     (-180) West ---+--- East (+180)
                                    |
                                    |
                                South (-90)