William Leite Araújo wrote:
On 15/03/07, *T E Schmitz* <[EMAIL PROTECTED]
<mailto:[EMAIL PROTECTED]>> wrote:
(...)
Try join the tables.
SELECT present.day, present.low, (MIN(future.day)-present.day) as
days2fall FROM history AS present JOIN history AS future ON (
present.day < future.day AND
future.low <= present.low )
GROUP BY present.day,present.low
ORDER BY days2fall DESC
That produces the same result as my previous example but maybe the join
is more efficient, Thank you for the suggestion.
However, I am still stuck as to how to retrieve HIGHEST. The result set
produced by the above query only contains those tuples whose LOW is
lower than present.LOW.
For HIGHEST, I need to look at the rows between present.day and DAYS2FALL:
something like
SELECT MAX (high) from history WHERE day >= present.day AND day <
(present.day + days2fall)
-
Regards,
Tarlika Elisabeth Schmitz
---------------------------(end of broadcast)---------------------------
TIP 9: In versions below 8.0, the planner will ignore your desire to
choose an index scan if your joining column's datatypes do not
match
