What is 2dsphere index in MongoDB?
A 2dsphere index supports queries that calculate geometries on an earth-like sphere. 2dsphere index supports all MongoDB geospatial queries: queries for inclusion, intersection and proximity. For more information on geospatial queries, see Geospatial Queries.
Can we update index in MongoDB?
To modify an existing index in MongoDB Compass, you need to drop and recreate the index. See also: MongoDB Compass Documentation. Compass Documentation for Indexes.
What is 2d sphere?
a 2-sphere is an ordinary 2-dimensional sphere in 3-dimensional Euclidean space, and is the boundary of an ordinary ball (3-ball). a 3-sphere is a 3-dimensional sphere in 4-dimensional Euclidean space.
What is a 2d index?
A 2d index can reference two fields. The first must be the location field. A 2d compound index constructs queries that select first on the location field, and then filters those results by the additional criteria.
What is geospatial indexing?
With the spatio-temporal library, you can use functions to index points within a region, on a region containing points, and points within a radius to enable fast queries on this data during location analysis. Perform the following steps to create and use a spatial index.
Do we need to rebuild index in MongoDB?
As per the MongoDB documentation, there is generally no need to routinely rebuild indexes.
How does a 2D index work?
A 2d index can reference two fields. The first must be the location field. A 2d compound index constructs queries that select first on the location field, and then filters those results by the additional criteria. A compound 2d index can cover queries.
What is R-tree indexing?
An index organizes access to data so that entries can be found quickly, without searching every row. The R-tree access method enables you to index multidimensional objects. Queries that use an index execute more quickly and provide a significant performance improvement.
Are MongoDB indexes strongly consistent?
Consistency. MongoDB is strongly consistent by default as all read/writes go to the primary in a MongoDB replica set, scaled across multiple partitions (shards). If desired, consistency requirements for read operations can be relaxed.
What are different types of indexes in MongoDB?
MongoDB provides a number of different index types to support specific types of data and queries.
- Single Field.
- Compound Index.
- Multikey Index.
- Geospatial Index.
- Text Indexes.
- Hashed Indexes.
How many types of indexing are there in MongoDB?
two types
To query geospatial data, MongoDB supports two types of indexes – 2d indexes and 2d sphere indexes.
What is the default version of a 2dsphere index?
Version 2 is the default version of 2dsphere indexes created in MongoDB 2.6 and 3.0 series. To override the default version and specify a different version, include the option { “2dsphereIndexVersion”: } when creating the index.
What is a compound 2dsphere index?
Unlike a compound 2d index which can reference one location field and one other field, a compound 2dsphere index can reference multiple location and non-location fields. For the following examples, consider a collection places with documents that store location data as GeoJSON Point in a field named loc:
Why can’t I have multiple 2dsphere Index in my collection?
If your collection has multiple 2dsphere index and/or multiple 2d index, you must use the key option to specify the indexed field path to use. If you do not specify the key, you cannot have multiple 2dsphere index and/or multiple 2d index since without the key, index selection among multiple 2d indexes or 2dsphere indexes is ambiguous.
Why can’t I use a 2dsphere index as a shard key?
If you do not specify the key, and you have at most only one 2dsphere index index and/or only one 2dsphere index index, MongoDB looks first for a 2d index to use. If a 2d index does not exists, then MongoDB looks for a 2dsphere index to use. You cannot use a 2dsphere index as a shard key when sharding a collection.