sediment A lakehouse table format you can watch

The table is the log.

A Delta table is not its data files. It is an ordered log of commits that say which files belong. This page runs that design for real: every statement you type lays down a new stratum, and time travel, concurrent writers, data skipping and VACUUM all fall out of replaying it. The table is two weeks of cloud usage records.

SQL console table: usage (day, workspace, sku, dbus, cost)

Two writers, one version

Both writers read the same version and both try to commit the next one. Storage lets exactly one of them create the file. The loser looks at what the winner did and either retries on top of it or gives up.

Transaction log

Newest on top. Click a layer to see the table as it was.

    Data files

    • in the table at this version
    • removed, kept on disk for time travel
    • deleted by VACUUM