Explanation of PostgreSQL Operations
Introduction This article will provide some basic concepts regarding the internal mechanics of PostgreSQL as a foundation for explanations in future articles. Heap First of all, it is necessary to distinguish the Heap in Postgres from Max-Heap or Min-Heap in data structures and algorithms, as well as Heap memory in RAM, they share the same name but are completely different. The meaning of the name Heap in Postgres signifies a jumble or a lack of order, because row data (called tuples) are stacked on top of each other randomly. In PostgreSQL, the Heap is the main storage area containing all the actual data of a table. When you create a table and INSERT rows of data, Postgres writes those rows into the Heap. Regarding storage, the Heap is simply one or more binary files created by Postgres when you insert data into a table. This Heap file is stored on disk and has a default limit of 1GB per file, if there is more data in the table, it will be split into multiple files for storage. Wherev...