Aus dem Kontext...

Manche Sätze sollte man lieber nicht aus dem Kontext reissen:

First, children are executed only sequentially, not concurrently.

 Dieser Satz stammt nicht aus einem Amnesty International-Bericht, sondern aus [1] auf Seite 245. Dort heißt der gesamte Absatz dann:

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When a parent transaction needs to roll back a sub-transaction, it uses a compensating sub-transaction to semantically undo the committed one instead of using a state-based undo. Multi-level transactions differ with respect to nested transactions in three aspects [49]. First, children are executed only sequentially, not concurrently. Second, all the leaf-level sub-transactions are at the same level in the transaction tree. Third, the commitment of a sub-transaction is unconditional, thereby making the result visible to other concurrently executing sub-transactions at the same level.
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Das klingt doch schon gleich viel besser...

[1]	T. Wang, J. Vonk, B. Kratz, and P. Grefen, “A survey on the history of transaction management: from flat to grid transactions,” Distributed and Parallel Databases, vol. 23, no. 3, pp. 235-270, Apr. 2008.