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04 Provenance and Audit Trails

Accounting got here first

The framing is claimed, canonically, since 2015. What survives is the part nobody implements.

Lesson 03 of 06 · 10 min

Before claiming this as an insight, know that it is claimed. Pat Helland, CIDR 2015, has a section titled "Accountants Don't Use Erasers" and another on observed versus derived facts.

The truth is the log. The database is a cache of a subset of the log.

Pat Helland, Immutability Changes Everything, CIDR 2015

Accountants don't use erasers or they go to jail. All entries in a ledger remain in the ledger. Corrections can be made but only by making new entries… When a company's quarterly results are published, they include small corrections to the previous quarter. Small fixes are OK! They are append-only, too!

Same paper

Cite him rather than arriving at it. Claiming novelty here is the kind of thing a reader corrects you on in public.

AccountingEngineering
EntryImmutable event
TransactionThe atomic commit; the unit of consistency
AccountAggregate, or stream identity
BalanceThe fold
Trial balanceA projection, plus its consistency check
Period closeA snapshot, made authoritative
JournalThe event log
Posting ruleThe apply function, versioned
Predict

The trial balance is the one row in that table with something engineering almost never implements. What is it?

The rest of this lesson unlocks when you commit above.