A series on understanding what is really happening under the hood of postgreSQL
Learn how PostgreSQL manages backend processes, the postmaster, shared buffers, and memory contexts. A deep dive into PG's process and memory model.
Explore how PostgreSQL stores data on disk - 8KB heap pages, item pointers, tuple headers, TOAST, and the free space map.
Understand how PostgreSQL implements MVCC using xmin/xmax, snapshot isolation, and visibility rules - with all four transaction isolation levels explained.
Deep dive into PostgreSQL's Write-Ahead Logging - how WAL records are written, what checkpoints do, and how crash recovery uses REDO to restore state.
Trace a SQL query through PostgreSQL's full pipeline - from raw text through the parser, rewriter, planner, and executor with internals at each stage.
Deep dive into index internals: B-tree page format, split algorithm, GIN posting lists, BRIN range summaries, and how the planner picks between the Indexes.
Inside PostgreSQL VACUUM: dead tuple collection, OldestXmin watermark, autovacuum triggers, XID freeze mechanics, bloat diagnosis, and pg_repack vs VACUUM FULL.
PostgreSQL locking deep dive: lock hierarchy, row-level locks in xmax, MultiXactId, deadlock detection, advisory locks, SKIP LOCKED queue, and pg_locks queries.
Final blog post of the PostgreSQL Internals series explaining about Replication and it's type i.e., Physical and Logical Replication.