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A comment on We Burned Down Players’ Houses in Ultima Online. Parent comment

Re:We Burned Down Players’ Houses in Ultima Online by Animats on Monday October 03, 2022 @11:45PM (#33076519)
No, a ledger and a database are different. The ledger is a transaction log. The database holds the current state.

Basic bookkeeping concept: every once in a while (usually daily) you take a snapshot of the current state and mark that point in the ledger. Then you take the previous snapshot, re-run the day's transactions, and you should get the current snapshot. If you don't, something has gone wrong. This is called "reconciliation".

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Re:We Burned Down Players’ Houses in Ultima Online by seanhunter on Tuesday October 04, 2022 @12:10AM (#33076632)
A database can hold state but it can also easily hold a ledger/transaction log. Or both. Most of the databases I have built or worked on end up organically evolving to have both "state tables" and "event tables" where event tables record state transitions broadly speaking. That's just a very natural way to model systems where you need to capture information about the state changes (eg when they happen etc).
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Re:We Burned Down Players’ Houses in Ultima Online by MereInterest on Monday October 03, 2022 @11:54PM (#33076558)
So, an append-only database.
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