Should failed completed transactions persist in the database?

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When I came across this statement I was confused, could anyone clarify?

Question: One of the known properties in relational databases as ACID is the durability, according to which, in a successfully completed transaction, all bank updates made by that transaction must persist.

(1) Unless there are other transactions running at the time of failure.

(2) Even in the occurrence of database system failures, after the end of the transaction.

The statement (1) or (2) or both are correct? What would be the justification?

If that’s the statement (2), perform persistence of failed transactions does not violate the property "C" relating to consistency?

For more information about the question, put here the origin of the inquiry.

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database acid

  • I don’t understand the negative

  • I didn’t either =(

  • I can only speculate on the negative. The introduction speaks in successfully completed transaction and the propositions speak in flaws, it makes no sense.

  • @Maniero in his opinion the Screens serve as an improvement to the issue?

  • In fact it’s D, but it’s debatable in the way it was placed.

1 answer

1


Durability is a property that must be guaranteed every time the transaction is completed, no matter what happens outside the transaction. So D is the right one.

The transaction is only completed in fact after it has become durable, that is, persisted. It is obvious that if a problem occurs after all necessary operations are completed and before durability is completed, ACID will not be met.

But it is questionable how it was put, gives room for interpretation, it seems that persistence is not part of the transaction.

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