Sql To Select Row From Each Day Of A Month

I have a table which store records of all dates of a month. I want to retrieve some data from it. The table is so large that I should only selecting a fews of them. If the records

Solution 1:

WITHTAS (
    SELECT ric_date
    FROM yourTable
    WHERE rice_date BETWEEN @start_date AND @end_date -- thanks Aaron Bertrand
    GROUP BY ric_date
)

SELECTCA.*
FROMTCROSSAPPLY (
    SELECT TOP 500 * -- 'a fews'
    FROM yourTable AS YT
    WHERE YT.ric_date = T.ric_date
    ORDER BY someAttribute -- not required, but useful
) ASCA

Solution 2:

Rough idea. This will get the first three rows per day for the current month (or as many that exist for any given day - there may be days with no rows represented).

DECLARE@manysINT=3, 
    @monthDATE= DATEADD(DAY, 1-DAY(GETDATE()), DATEDIFF(DAY, 0, GETDATE()));

;WITH x AS 
(
  SELECT some_column, ric_date, rn =ROW_NUMBER() OVER 
    (PARTITIONBY ric_date ORDERBY ric_date)
  FROM dbo.data 
  WHERE ric_date >=@monthAND ric_date < DATEADD(MONTH, 1, @month)
)
SELECT some_column, ric_date FROM x
WHERE rn <=@manys;

If you don't have supporting indexes (most importantly on ric_date), this won't necessarily scale well at the high end.