How can full-text search be performed in MongoDB?

Full-text search in MongoDB is efficiently performed by creating text indexes for string content. This capability is specifically designed to handle queries that involve searching for text within string fields.

When you create a text index on a collection, MongoDB processes and stores the indexed content, enabling it to search for words or phrases across documents quickly. This index facilitates operations like finding documents that match certain keywords, phrases, or even performing stemming and text score calculations for relevance in search results.

Using text indexes allows for more advanced search functionalities, such as stemmed word searches, where variations of a word can be matched against the indexed content, as well as support for string tokenization techniques like removing stop words.

The other methods mentioned, such as indexing with unique identifiers or running complex aggregation queries, do not provide the same level of text search capabilities as specialized text indexing. While external search engines can enhance search functionality, MongoDB's native text indexing feature is specially designed for full-text search needs within its own database environment.