PostgreSQL Heap-Only-Tuple or HOT Update Optimization
Introduction In this article, we are going to analyze how PostgreSQL Heap-Only-Tuple or HOT Update optimization works, and why you should avoid indexing columns that change very frequently.
PostgreSQL Index Types
Introduction In this article, we are going to analyze the PostgreSQL Index Types so that we can understand when to choose one index type over the other. When using a relational database system, indexing is a very important topic because it can help you speed up your SQL queries by reducing the number of pages that have to be scanned or even avoid some operations altogether, such as sorting. If you want to receive automatic index and SQL rewrite recommendations based on your database workloads, check out EverSQL by Aiven.
Index Selectivity
Introduction In this article, we are going to see how Index Selectivity works in relational database systems and why the database Optimizer might choose to avoid using an index if the number of matching records is large. Index selectivity is inversely proportional to the number of index entries matched by a given value. So, a unique index has the highest selectivity because only a single entry can be matched by any given value. On the other hand, if column values are skewed, then a column value matching a large number of table… Read More
