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  1. OMG Issue

QVT14 — Trace Record not suitable for Incremental Execution

  • Key: QVT14-15
  • Status: open  
  • Source: Model Driven Solutions ( Dr. Edward Willink)
  • Summary:

    The glossary definition of Incremental Update strongly suggests that the trace necessary to execute a transformation is also suitable for incremental execution. This is a total falacy.

    Incremental execution of a Rule R with an input s must occur if any relevant property of s changes, which includes any property navigable from s. e.g. s.a.b.c.name. Therefore the trace for incremental execution must identify the identity and value of all accessed property values so that any change can influence re-execution.

    Since accessed values may be produced by another mapping, the trace must also record the identity and value of all assigned property values too.

    This affects all of QVTc, QVTr, and QVTo.

    For QVTo, a re-execution must repeat the accidental ordering of Set elements. Does the specification define an order or just require implementation magic? Is this then a determinstic form of asOrderedSet()?

  • Reported: MOF 1.2 — Wed, 28 Oct 2015 19:10 GMT
  • Updated: Tue, 22 Dec 2015 15:31 GMT