An inverted index is a type of database index that enhances text search efficiency by storing the locations of search terms within a table, allowing for quick retrieval without the need for full table scans. This is particularly beneficial in large databases where scanning every row would be time-consuming. The primary advantage of inverted indexes is their ability to significantly improve read performance during text searches, although they can slightly slow down write operations because new data must be added to the index. Despite this downside, the performance gains often outweigh the costs, especially in read-heavy applications. Inverted indexes work well with various data types and can be optimized further using techniques like stemming and lemmatization to refine search capabilities. Creating these indexes in SQL requires specific syntax that may vary depending on the database system, such as CockroachDB, which supports advanced indexing features and compatibility with PostgreSQL.