[jira] [Created] (CALCITE-1872) PREV is parsed as LAST when the name of the pattern referenced is not the same with the pattern being defined

["Dian Fu (JIRA)" <ji...@apache.org>]

Dian Fu created CALCITE-1872:
--------------------------------

             Summary: PREV is parsed as LAST when the name of the pattern referenced is not the same with the pattern being defined
                 Key: CALCITE-1872
                 URL: https://issues.apache.org/jira/browse/CALCITE-1872
             Project: Calcite
          Issue Type: Bug
            Reporter: Dian Fu
            Assignee: Julian Hyde


For table {{Ticker}}:
{code}
symbol: string
tstamp: long
price: int
{code}
, the {{UP}} in the following sql
{code}
SELECT *
FROM Ticker
MATCH_RECOGNIZE (
  MEASURES
    STRT.tstamp AS start_tstamp,
    LAST(DOWN.tstamp) AS up_days,
    LAST(UP.tstamp) AS total_days
  PATTERN (STRT DOWN+ UP+)
  DEFINE
    DOWN AS DOWN.price < PREV(DOWN.price),
    UP AS UP.price > PREV(DOWN.price)
) AS T
{code}
is parsed as
{code}
">(PREV(UP.$2, 0), LAST(DOWN.$2, 1))"
{code}
I think this is not correct. PREV defines a physical offset, while LAST defines a logical offset.



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