The simulator visualizes how a database maintains multiple timestamped versions of a row and routes each transaction to the version matching its own snapshot, showing readers and writers proceeding concurrently without blocking each other.
Start transactions, issue reads and writes against shared rows, and watch how each transaction's snapshot determines which row version it sees, then trigger vacuum to clean up dead tuples.
Controls let you launch concurrent transactions, perform reads and writes, and manually trigger vacuum to observe snapshot visibility and dead tuple cleanup in real time.
PostgreSQL's autovacuum process can fall dangerously behind if a single transaction stays open for hours, since it forces the database to retain every row version that transaction might still need to see.
The simulator visualizes how a database maintains multiple timestamped versions of a row and routes each transaction to the version matching its own snapshot, showing readers and writers proceeding concurrently without blocking each other.
The simulator visualizes how a database maintains multiple timestamped versions of a row and routes each transaction to the version matching its own snapshot, showing readers and writers proceeding concurrently without blocking each other.
Start transactions, issue reads and writes against shared rows, and watch how each transaction's snapshot determines which row version it sees, then trigger vacuum to clean up dead tuples.
PostgreSQL's autovacuum process can fall dangerously behind if a single transaction stays open for hours, since it forces the database to retain every row version that transaction might still need to see.