panosfol commented on issue #354: URL: https://github.com/apache/age/issues/354#issuecomment-1437591233
_Here is a summary of the first 3 chapters of the Internals of PostgreSQL:_ **Chapter 1** introduces the logical structure of the database clusters each with their own collection of databases and database objects and then focuses on the physical structure of how the base directory and the subdirectories work with each other. Also it analyzes the internal layout of a data file, focusing on the heap table file. Lastly it mentions the methods of writing and reading heap tuples. **Chapter 2** focuses on the processes that run on a PostgreSQL server especially on the server process, the backend processes and the background processes. Also it discusses the memory architecture in PostgreSQL dividing into to areas, the local memory area, allocated by each backend process for its own use, and the shared memory area, used by all processes of a PostgreSQL server. **Chapter 3** delves deeper into a more complex subsystem of the PostgreSQL, the query processing and especially the query optimization. This chapter focuses around the 5 subsystems: the parser, the analyzer, the rewriter, the planner and the executor and how each system contributes to the execution of a given query. Then it focuses on the cost estimation of a single-table query and how does the planner calculates and creates the plan tree. After that it analyzes the executor and the join operations, focusing on the nested loop join, the merge join and the hash join. The chapter closes with an explanation of a plan tree of a multiple-table query. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: dev-unsubscr...@age.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org
