Add missing index to MDM Windows enrollments table (#17559)

changes/16120-add-windows-mdm-support-to-osquery-perf

@@ -1 +1,2 @@
 * Added Windows MDM support to the `osquery-perf` host-simulation command.
+* Added a missing database index to the MDM Windows enrollments table that will improve performance at scale.

server/datastore/mysql/migrations/tables/20240312103753_AddMDMWindowsEnrollmentsIndex.go

@@ -0,0 +1,25 @@
+package tables
+
+import (
+	"database/sql"
+	"fmt"
+)
+
+func init() {
+	MigrationClient.AddMigration(Up_20240312103753, Down_20240312103753)
+}
+
+func Up_20240312103753(tx *sql.Tx) error {
+	_, err := tx.Exec(`
+	ALTER TABLE mdm_windows_enrollments
+		ADD INDEX idx_mdm_windows_enrollments_mdm_device_id (mdm_device_id)`,
+	)
+	if err != nil {
+		return fmt.Errorf("failed to add index to mdm_windows_enrollments.mdm_device_id: %w", err)
+	}
+	return nil
+}
+
+func Down_20240312103753(tx *sql.Tx) error {
+	return nil
+}