PostgreSQL 18 introduces significant improvements to the btree_gist extension, primarily through the implementation of sortsupport, which enhances index building efficiency. These updates enable better performance for use cases such as nearest-neighbour search and exclusion constraints, offering notable gains in query throughput compared to previous versions.

The article explores the use of custom ICU collations with PostgreSQL's citext data type, highlighting performance comparisons between equality, range, and pattern matching operations. It concludes that while custom collations are superior for equality and range queries, citext is more practical for pattern matching until better index support for nondeterministic collations is achieved.

PostgreSQL's Index Only Scan enhances query performance by allowing data retrieval without accessing the table heap, thus eliminating unnecessary delays. It requires specific index types and query conditions to function effectively, and the concept of a covering index, which includes fields in the index, further optimizes this process. Understanding these features is crucial for backend developers working with PostgreSQL databases.

Data types significantly influence the performance and efficiency of indexing in PostgreSQL. The article explores how different data types, such as integers, floating points, and text, affect the time required to create indexes, emphasizing the importance of choosing the right data type for optimal performance.

Understanding when to rebuild PostgreSQL indexes is crucial for maintaining database performance. The decision depends on index type, bloat levels, and performance metrics, with recommendations to use the `pgstattuple` extension to assess index health before initiating a rebuild. Regular automatic rebuilds are generally unnecessary and can waste resources.