mongodb sparse compound index

First, the index introductionIn MongoDB, indexes are used to support efficient queries. If there is no index, MONGODB must scan each document in the entire collection to find a matching document. However, if an appropriate index is established,

Indexes can often greatly improve the efficiency of queries, and if there is no index, MongoDB must scan every file in the collection and select those records that meet the query criteria when reading the data. This scan full set of query efficiency

Previous wordsIndexes can often greatly improve the efficiency of queries, and if there is no index, MongoDB must scan every file in the collection and select those records that meet the query criteria when reading the data. This scan full set of

Index typeMONGDB indexes are divided into the following types: Single-key index, composite index, geospatial Index, full-text index, and hash indexSingle-key index (single Field Indexes)An index created on a key is a single-key index, which is the

One, index type (a), one -touch index The index created on one key is the one-touch index, and the single key index is the most common index, such as the _id index created by default by MongoDB. (ii), composite index Indexes built on multiple keys

MongoDB data model and index learning summary, mongodb ModelMongoDB data model and index learning Summary 1. MongoDB Data Model: MongoDB data storage structure:MongoDB uses BSON (binary json, binary encoding) data format for document (large files

MongoDB Data Model and Index learning Summary 1. MongoDB Data Model: MongoDB Data storage structure:MongoDB uses Bson (binary JSON, binary encoded) data format to store and exchange data for documents (large files using the GRIDFS protocol).

Indexes in MongoDB are similar to other database indexes and are also used with the b-tree structure. The index of MongoDB is at the collection level and supports the creation of indexes in the sub-columns of any column or document within the

Index is like the directory of books, if the search for a content without the help of the directory, can only look through the entire page, which led to the very low efficiency; If you use the directory, you can quickly locate the specific content

Version: mongodb3.4; Index :If MongoDB cannot sort using an index, the data is placed in memory for sorting, and when memory usage exceeds 32MB, an error is made.When you create an index, you should ensure that the index is selected to avoid