[jira] [Created] (CALCITE-1871) Nesting LAST within PREV is not parsed correctly for MATCH_RECOGNIZE

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

Dian Fu created CALCITE-1871:
--------------------------------

             Summary: Nesting LAST within PREV is not parsed correctly for MATCH_RECOGNIZE
                 Key: CALCITE-1871
                 URL: https://issues.apache.org/jira/browse/CALCITE-1871
             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 bottom_tstamp,
    LAST(UP.tstamp) AS end_tstamp
  ONE ROW PER MATCH
  PATTERN (STRT DOWN+ UP+)
  DEFINE
    DOWN AS DOWN.price < PREV(DOWN.price),
    UP AS UP.price > PREV(LAST(DOWN.price, 1), 1)
) AS T
{code}
is parsed as follows:
{code}
">(PREV(UP.$2, 0), LAST(DOWN.$2, 1))"
{code}
I think this is not as expected. According to the documentation about MATCH_RECOGNIZE, it supports nesting {{LAST}}/{{FIRST}} within {{PREV}}/{{NEXT}} and we should not just ignore the {{PREV}}.



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