Query based on two views

Question

Hello ppl, I need your help.
I got this query which is based on two views.
View_1: x1, x2, x3, x4, day, xy
View_2: y1, y2, y3, y4, day, xy
By running a SELECT query on each view takes approx 2 minutes, yes there are lots of records.
When I combine the query most of the time it times out. I think there is something wrong with my query.
View_1 = View_2 on col xy and day, however I have to get the records from View_2 for the following day, i.e if day = 3 from View_1 and the record from View_2 should be coming from view_2
at present my query is like this
SELECT a.x1, a.x2, a.x3, a.x4, a.day, a.xy, b.y1, b.y2
FROM view_1 a, view_2 b
WHERE b.y2= 100
AND a.xy = b.xy
AND b.y1 = ( SELECT b.y1
FROM view_1 a, view_2 b
WHERE b.day = a.day + 1)
ORDER BY a.x1
This query gets called in a coldfusion page.
P.S I can also ask the DBA to make me a new view based on the same columns as the query. Would that help with speed?

Answer 1

I don't see any reason why my query shouldn't give
you what you desire.
View_1
x1     x2     x3     x4     Day     XY
2      3      23      32      3      2132
3      3      2      3      4      2132
4      3      43      32      5      2132
View_2
y1     y2     y3     y4     Day     XY
4      100      13      32      3      2132
5      100      4      3      4      2132
7      100      43      32      5      2132
5      100      23      12      6      2132
Is it a coincidence that XY has the same value in your sample? Could it be different
and at the same time participate in the desired result?
SELECT     a.x1, a.x2, a.x3, a.x4, a.day, a.xy, b.y1, b.y2
FROM     view_1 a
,     view_2 b
WHERE     b.y2 = 100
AND     a.xy = b.xy
AND     b.day = a.day + 1
ORDER BY a.x1
>
X1     X2     X3     X4     Day     XY     y1     y2
2      3      23     32      3      2132      5      100
3      3      2      3      4      2132      7      100
4      3      43     32      5      2132      5      100
According to the reply to my question above, it can be ok or not.
That is why I proposd this (in case the reply were yes):
SELECT a.x1, a.x2, a.x3, a.x4, a.day, a.xy, b.y1, b.y2
FROM view_1 a, view_2 b, vew_1 c
WHERE b.y2= 100
AND a.xy = b.xy
AND b.day = c.day + 1
ORDER BY a.x1