>>>>> "Alvaro" == Alvaro Herrera <alvhe...@2ndquadrant.com> writes:
Alvaro> First, I noticed that there's a significant unanswered issue Alvaro> from Andrew Gierth about this using a completely different Alvaro> mechanism, namely an implicit window function. Robert was Alvaro> concerned about the performance of Andrew's proposed approach, Alvaro> but I don't see any reply from Surafel on the whole issue. Alvaro> Andrew: Would you rather not have this feature in this form at Alvaro> all? I have done a proof-of-concept hack for my alternative approach, which I will post in another thread so as not to confuse the cfbot. The main advantage, as I see it, of a window function approach is that it can also work for PERCENT with only a change to the generated expression; the executor part of the code can handle any stopping condition. It can also be generalized (though the POC does not do this) to allow an SQL-level extension, something like "LIMIT WHEN condition" to indicate that it should stop just before the first row for which the condition is true. Whether this is a desirable feature or not is another question. -- Andrew.
