C100DEV Indexing Practice Question

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

• ✗

  Text index

  Why it's wrong here

  Text indexes are designed for searching string content and performing full-text search operations. They do not support geospatial operators like $near or $geoWithin, which require specialized structures to calculate distances on a curved surface efficiently and accurately for location-based data points within a database collection.

• ✗

  Hashed index

  Why it's wrong here

  Hashed indexes provide efficient equality matches by hashing the value of a field. They do not support range-based queries or geospatial calculations. Using a hashed index for coordinates would prevent the database from utilizing proximity-based query operators required for location-aware applications, leading to full collection scans.

• ✓

  2dsphere index

  Why this is correct

  The 2dsphere index supports queries that interpret data as points on an earth-like sphere. It is the primary index type for geolocation data, enabling operations like $nearSphere, $geoWithin, and $geoIntersects, which are necessary for calculating distances and boundaries between various geographic coordinates efficiently.

• ✗

  Compound index

  Why it's wrong here

  While compound indexes allow indexing multiple fields, they do not inherently provide the geospatial math capabilities required for coordinates. You would need to include a 2dsphere index within a compound structure to achieve geospatial functionality, making this option less specific and accurate than the required index type.