Brain indexes and their advantages

Brain indexes offer a smaller index size compared to B-trees, making them attractive for tables with large volumes of data. However, they may not be as efficient as B-trees for point searches where only a few rows need to be retrieved. Brain indexes are more suitable for tables with a log or telemetry pattern, where data is inserted or updated frequently. It is important to note that brain indexes require a strong correlation with the physical storage layout, so reindexing or clustering the table may be necessary for optimal performance. The inclusion of new improvements in Postgres 14, such as the min max multi operator class, allows brain indexes to support different types of correlations and have better overall performance.