PostgreSQL — Engine Visualizer

psql terminal postgres@postgres

PGDATA · visual layout click any card to jump to a detailed view

PGDATA /var/lib/postgresql/16/main the single folder where all your databases physically live

heap index FSM VM WAL / CLOG page touched dead page

psql terminal postgres@localhost

PGDATA /var/lib/postgresql/16/main — pages —

inspector click any file or page byte

heap pages 8192 B / page

page layout

pg_wal records 16 MB / segment

record detail

B-tree indexes

structure

T1 xid — idle snapshot —

locks held: —

T2 xid — idle snapshot —

locks held: —

PostgreSQL engine network scenario — pick one above

Pick a scenario above to see one ACID property demonstrated atom by atom.

Recent atomic ops · particle log

postgres · idle

+0.00s

Press ▶ run to walk through the script. Each command emits a sequence of low-level operations: WAL append → page modify → CLOG update → buffer fsync.