Hi Tatsuo,
> What do you mean by "Anchored pattern" here? I am asking because R010 > (RPR in Window clause) does not allow to use anchors (^ and $) in > PATTERN clause. > Good catch - the term "anchored pattern" is indeed confusing here. You're absolutely right that SQL:2023 R010 does not allow regex anchors (^ and $) in the PATTERN clause. In this context, I was using "anchored" to mean "a pattern that starts with a PREFIX element" - not referring to regex anchors at all. The example "START A+ B" has a PREFIX element (START) that "anchors" the pattern matching to begin at a specific point. To avoid confusion with SQL regex anchors, I suggest we change the terminology: "Anchored pattern" → "Pattern with PREFIX" or "PREFIX-led pattern" "Anchored pattern absorption" → "PREFIX pattern absorption optimization" The optimization issue remains the same: PREFIX elements block the absorption mechanism, requiring the "shadow path" approach to maintain O(n) complexity while processing patterns like "START A+ B". Does this clarification make sense? Best regards, Henson
