MongoDB Indexes II

In this unit, you learned how to:

• Identify which fields in the explain() output will indicate a performance issue, i.e. nReturned, totalDocsExamined, totalKeysExamined
• Set the verbosity level for explain(), i.e. executionStats
• Run explain() on a query to determine if the query is using an index
• Read the explain() output run on a query and identify what index a query is using
• Create an efficient compound index for a given query
• Create a wildcard index
• Create a partial index
• Create a sparse index
• Create a clustered time series index
• Use $indexStats to view the indexes with the most operations and unused indexes in a collection
• Enable profiling and set the profiling level using db.setProfilingLevel()
• Use Database Profiler (system.profile collection) to identify slow queries

Resources

Use the following resources to learn more about Indexing with MongoDB:

Lesson 1: How Indexes Work

• Indexes in MongoDB
• What is Indexing in a Database?
• Compound Indexes
• MongoDB University: Indexing I (Prerequisite course)
• Index Best Practices

Lesson 2: Index Usage Details via Explain

• Explain Method
• Explain Verbosity Levels
• Explain Results
• Query Plans

Lesson 3: Optimized Compound Indexes

• Compound Indexes
• The ESR (Equality Sort Range) Rule
• Tips and Tricks for Effective Indexing
• Create Indexes to Support Your Queries

Lesson 4: Wildcard Indexes

• Wildcard Indexes in MongoDB
• Create a WildCard Index on All Fields
• Include or Exclude Fields in a Wildcard Index
• Wildcard Index Restrictions
• Compound Wildcard Indexes (new in 7.0)

Lesson 5: Partial Indexes

• Partial Indexes in MongoDB
• Partial Index Restrictions

Lesson 6: Sparse Indexes

• Sparse Indexes in MongoDB
• Indexes that are Sparse by Default

Lesson 7: Clustered Indexes

• Clustered Collections in MongoDB
• Clustered Index Reference
• expireAfterSeconds
• Clustered Collection Examples

Lesson 8: Time Series Collections

• Time Series
• Create a Time-Series Collection
• Add Secondary Indexes to Time-Series Collections
• List Time-Series Collections in a Database
• Set up Automatic Removal
• Time Series Product Overview

Lesson 9: How to Monitor Indexes

• $indexStats Operator
• MongoDB Database Profiler
• Reading Profiler Output
• db.setProfilingLevel()
• Database Profiler Verbosity Levels