How to force sql server to use the spatial index?

Getting SQL Server to Play Nice with Your Spatial Index: A Human’s Guide

Spatial data in SQL Server? It’s incredibly powerful for location-based insights. But let’s be honest, sometimes SQL Server’s query optimizer… well, it doesn’t always pick the smartest route, especially when it comes to using those spatial indexes. The result? Queries that take way longer than they should. So, how do we convince it to use those indexes and get the performance we deserve? That’s what we’re diving into.

First, a quick refresher. Spatial indexes are special. They’re designed to make spatial queries – you know, the ones dealing with geometry and geography data – lightning fast. Think of them as a super-organized map that helps SQL Server quickly pinpoint data within a specific area.

Now, the query optimizer. This is the brain that figures out the best way to execute your query. It’s usually pretty good, but it relies on estimations. And sometimes, those estimations for spatial stuff? They’re just plain wrong. That’s when it decides to ignore your perfectly good spatial index. Frustrating, right?

Alright, let’s get practical. Here are some tricks I’ve learned over the years to “encourage” SQL Server to use that spatial index.

1. The Index Hint: A Gentle Nudge (or a Firm Shove)

This is the most direct approach. You’re basically telling SQL Server, “Hey, use this index.” You do it with the WITH (INDEX(index_name)) clause in your FROM clause. Like this:

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