Dian Fu created CALCITE-1871:
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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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