What types of indexes have you used in your projects?

The following types of indexes are usually used in Go projects:

• Database indexes (e.g., B-trees, hash indexes) to speed up queries to SQL or NoSQL databases.
• Indexes in search engines (e.g., inverted indexes for full-text search).
• Indexes in data structures, such as maps, for quick access by key.

Example of using an index in a database with Go and SQL:

rows, err := db.Query("SELECT * FROM users WHERE email = ?", email)
// Here, an index on the email field will speed up the search

Also, in Go, you can implement your own in-memory indexes to optimize search in slices or structures.