August 17, 2012 at 11:25 am
I need to query some tables looking for All Sales that are active at the same time and have at least one Location in common and at least one Item in common. I have a query that does this, but it actually counts all the common Items on Sale at each Location and this is taking too much time in the large tables that I have to query. I feel like their should be a way to restructure my query approach so that only the first common item would need to be found rather than all common items.
I'm looking for ways to improve the performance of my query approach.
Here is a simple representation of my data and existing query:
[font="Courier New"]
drop table SaleLocationXref
drop table Sale
drop table SaleItemXref
create table SaleLocationXref (
SaleID int not null,
LocationID int not null,
constraint SaleLocationXref_PK primary key (SaleID,LocationID)
)
create table Sale (
SaleID int not null,
SaleStart datetime not null,
SaleEnd datetime not null,
constraint Sale_PK primary key (SaleID)
)
create table SaleItemXref (
SaleID int not null,
ItemID int not null,
constraint SaleItemXref_PK primary key (SaleID,ItemID)
)
insert into SaleLocationXref values (1,1),(2,1),(4,1),(5,1),
(3,2)
insert into Sale values (1,'01/01/2012','01/07/2012'),
(2,'01/06/2012','01/10/2012'),
(3,'01/01/2012','02/07/2012'),
(4,'02/08/2012','02/15/2012'),
(5,'01/09/2012','01/16/2012')
insert into SaleItemXref values (1,1),(1,2),(1,3),
(2,1),(2,4),(2,5),
(3,5),(3,6),(3,7),
(4,5),(4,6),(4,7),
(5,7),(5,8),(5,1)
select distinct SaleID, LocationID
from (
select SIX.SaleID, LocationID, ItemID,
Count(*) over (partition by LocationID, ItemID) as Cnt
from SaleItemXref SIX
join (
select distinct S1.SaleID, SLX1.LocationID
from Sale S1
join Sale S2 -- Compare sales
on S1.SaleID <> S2.SaleID
and (S1.SaleStart <= S2.SaleEnd -- Compare dates overlap
and S2.SaleStart <= S1.SaleEnd)
join SaleLocationXref SLX1
on S1.SaleID = SLX1.SaleID
join SaleLocationXREF SLX2
on S2.SaleID = SLX2.SaleID
and SLX1.LocationID = SLX2.LocationID -- Compare location overlap
) #SaleOverlap
on #SaleOverlap.SaleID = SIX.SaleID
) ItemOverlap
where ItemOverlap.Cnt > 1 -- Compare item overlap
[/font]
August 17, 2012 at 12:31 pm
If there are 3 SalesID's with 1 item in common but the overlap is for only 2 of the SalesID's, does that need to be reported or does the over lap have to occur for all SlaesID with that item?
In your sample data look at SaleID 2,3, and 4 and ItemID 5. The SaleID 2 and 3 overlap each other but 4 doesn't.
August 17, 2012 at 2:49 pm
Using what you provided, I actually came up with the following.
create table SaleLocationXref (
SaleID int not null,
LocationID int not null,
constraint SaleLocationXref_PK primary key (SaleID,LocationID)
);
create table Sale (
SaleID int not null,
SaleStart datetime not null,
SaleEnd datetime not null,
constraint Sale_PK primary key (SaleID)
);
create table SaleItemXref (
SaleID int not null,
ItemID int not null,
constraint SaleItemXref_PK primary key (SaleID,ItemID)
);
insert into SaleLocationXref
values (1,1),(2,1),(4,1),(5,1),(3,2);
insert into Sale
values (1,'01/01/2012','01/07/2012'),
(2,'01/06/2012','01/10/2012'),
(3,'01/01/2012','02/07/2012'),
(4,'02/08/2012','02/15/2012'),
(5,'01/09/2012','01/16/2012');
insert into SaleItemXref
values
(1,1),(1,2),(1,3),
(2,1),(2,4),(2,5),
(3,5),(3,6),(3,7),
(4,5),(4,6),(4,7),
(5,7),(5,8),(5,1);
GO
with BaseData as (
select
six.ItemID,
six.SaleID,
s.SaleStart,
s.SaleEnd,
count(*) over (partition by six.ItemID) as ItemCnt
from
Sale s inner join SaleItemXref six
on (s.SaleID = six.SaleID)
)
select distinct
bd1.ItemID,
bd1.SaleID,
slx.LocationID,
bd1.SaleStart,
bd1.SaleEnd
from
BaseData bd1
inner join BaseData bd2
on (bd1.ItemID = bd2.ItemID
and bd1.SaleID <> bd2.SaleID)
inner join SaleLocationXref slx
on (slx.SaleID = bd1.SaleID)
where
bd1.ItemCnt > 1
and (bd1.SaleStart between bd2.SaleStart and bd2.SaleEnd or
bd2.SaleStart between bd1.SaleStart and bd1.SaleEnd)
order by
bd1.ItemID,
bd1.SaleID;
GO
drop table SaleLocationXref;
drop table Sale;
drop table SaleItemXref;
GO
August 17, 2012 at 4:46 pm
Celko,
Thank you for your reply. I'm familiar with your work and am honored that you took the time to reply to this post. If you have a way to utilize EXISTS() (or TOP) to solve the query problem, then I hope you will share it. I would be very interested in that type of solution.
Lynn,
Thank you for your reply. It made me realize that my description of the result I was looking for was not accurate. I should have said:
I need a query to find "All Sales that are active at the same time and have at least one Location in common and at least one Item in common."
Forgive me for that. I'll try to edit my original post.
August 19, 2012 at 12:11 pm
Celko,
I really appreciate the idea. I tried it:
select ...
where EXISTS (select f1.item_id INTERSECT select f2.item_id)
It sounded like it could potentially offer much better performance, but it appeared to perform exactly the same as an inner join
select ...
join ...
on f1.item_id = f2.item_id
I'm still working to try and formulate some solution with accepatable performacne, so if you or anyone else might have another idea, I would really appreciate hearing about it.
August 19, 2012 at 7:30 pm
I took a shot at it with this:
;WITH Sale AS (
SELECT a.SaleID, a.SaleStart, a.SaleEnd, b.LocationID, c.ItemID
FROM #Sale a
JOIN #SaleLocationXref b ON a.SaleID = b.SaleID
JOIN #SaleItemXref c ON c.SaleID = a.SaleID
)
SELECT SaleID, LocationID
FROM (
SELECT a.SaleID, a.SaleStart, a.SaleEnd, a.LocationID, a.ItemID
, SaleID2=b.SaleID, LocationID2=b.LocationID, ItemID2=b.ItemID
,n=ROW_NUMBER() OVER (PARTITION BY a.SaleID, a.LocationID ORDER BY (SELECT NULL))
FROM Sale a
CROSS APPLY (
SELECT SaleID, LocationID, ItemID
FROM Sale b
WHERE (b.SaleStart BETWEEN a.SaleStart AND b.SaleEnd OR
b.SaleEnd BETWEEN a.SaleStart AND b.SaleEnd) AND a.SaleID <> b.SaleID) b
WHERE a.LocationID = b.LocationID AND a.ItemID = b.ItemID) c
WHERE n=1
Unfortunately mine is significantly slower than yours though. You can test with this test harness:
create table #SaleLocationXref (
SaleID int not null,
LocationID int not null,
constraint SaleLocationXref_PK primary key (SaleID,LocationID)
)
create table #Sale (
SaleID int not null,
SaleStart datetime not null,
SaleEnd datetime not null,
constraint Sale_PK primary key (SaleID)
)
create table #SaleItemXref (
SaleID int not null,
ItemID int not null,
constraint SaleItemXref_PK primary key (SaleID,ItemID)
)
insert into #SaleLocationXref values (1,1),(2,1),(4,1),(5,1),
(3,2)
insert into #Sale values (1,'01/01/2012','01/07/2012'),
(2,'01/06/2012','01/10/2012'),
(3,'01/01/2012','02/07/2012'),
(4,'02/08/2012','02/15/2012'),
(5,'01/09/2012','01/16/2012')
insert into #SaleItemXref values (1,1),(1,2),(1,3),
(2,1),(2,4),(2,5),
(3,5),(3,6),(3,7),
(4,5),(4,6),(4,7),
(5,7),(5,8),(5,1)
;WITH Tally (n) AS (
SELECT TOP 10000 10+ROW_NUMBER() OVER (ORDER BY (SELECT NULL))
FROM sys.all_columns t1 CROSS JOIN sys.all_columns t2)
INSERT INTO #SaleLocationXref
SELECT DISTINCT SaleID * n, LocationID * n
FROM #SaleLocationXref
CROSS APPLY Tally
;WITH Tally (n) AS (
SELECT TOP 10000 10+ROW_NUMBER() OVER (ORDER BY (SELECT NULL))
FROM sys.all_columns t1 CROSS JOIN sys.all_columns t2)
INSERT INTO #Sale
SELECT SaleID, SaleStart, SaleEnd
FROM (
SELECT SaleID=SaleID * n, SaleStart, SaleEnd
,n=ROW_NUMBER() OVER (PARTITION BY SaleID * n ORDER BY (SELECT NULL))
FROM #Sale
CROSS APPLY Tally) a
WHERE n = 1
;WITH Tally (n) AS (
SELECT TOP 10000 10+ROW_NUMBER() OVER (ORDER BY (SELECT NULL))
FROM sys.all_columns t1 CROSS JOIN sys.all_columns t2)
INSERT INTO #SaleItemXref
SELECT DISTINCT SaleID * n, ItemID * n
FROM #SaleItemXref
CROSS APPLY Tally
DECLARE @Holder1 INT, @Holder2 INT
PRINT '---- Revised query'
SET STATISTICS TIME ON
;WITH Sale AS (
SELECT a.SaleID, a.SaleStart, a.SaleEnd, b.LocationID, c.ItemID
FROM #Sale a
JOIN #SaleLocationXref b ON a.SaleID = b.SaleID
JOIN #SaleItemXref c ON c.SaleID = a.SaleID
)
SELECT @Holder1=SaleID, @Holder2=LocationID
FROM (
SELECT a.SaleID, a.SaleStart, a.SaleEnd, a.LocationID, a.ItemID
, SaleID2=b.SaleID, LocationID2=b.LocationID, ItemID2=b.ItemID
,n=ROW_NUMBER() OVER (PARTITION BY a.SaleID, a.LocationID ORDER BY (SELECT NULL))
FROM Sale a
CROSS APPLY (
SELECT SaleID, LocationID, ItemID
FROM Sale b
WHERE (b.SaleStart BETWEEN a.SaleStart AND b.SaleEnd OR
b.SaleEnd BETWEEN a.SaleStart AND b.SaleEnd) AND a.SaleID <> b.SaleID) b
WHERE a.LocationID = b.LocationID AND a.ItemID = b.ItemID) c
WHERE n=1
SET STATISTICS TIME OFF
PRINT '---- Original query'
SET STATISTICS TIME ON
select distinct @Holder1=SaleID, @Holder2=LocationID
from (
select SIX.SaleID, LocationID, ItemID,
Count(*) over (partition by LocationID, ItemID) as Cnt
from #SaleItemXref SIX
join (
select distinct S1.SaleID, SLX1.LocationID
from #Sale S1
join #Sale S2 -- Compare sales
on S1.SaleID <> S2.SaleID
and (S1.SaleStart <= S2.SaleEnd -- Compare dates overlap
and S2.SaleStart <= S1.SaleEnd)
join #SaleLocationXref SLX1
on S1.SaleID = SLX1.SaleID
join #SaleLocationXREF SLX2
on S2.SaleID = SLX2.SaleID
and SLX1.LocationID = SLX2.LocationID -- Compare location overlap
) #SaleOverlap
on #SaleOverlap.SaleID = SIX.SaleID
) ItemOverlap
where ItemOverlap.Cnt > 1 -- Compare item overlap
SET STATISTICS TIME OFF
PRINT '---- Original query with MAXDOP 1'
SET STATISTICS TIME ON
select distinct @Holder1=SaleID, @Holder2=LocationID
from (
select SIX.SaleID, LocationID, ItemID,
Count(*) over (partition by LocationID, ItemID) as Cnt
from #SaleItemXref SIX
join (
select distinct S1.SaleID, SLX1.LocationID
from #Sale S1
join #Sale S2 -- Compare sales
on S1.SaleID <> S2.SaleID
and (S1.SaleStart <= S2.SaleEnd -- Compare dates overlap
and S2.SaleStart <= S1.SaleEnd)
join #SaleLocationXref SLX1
on S1.SaleID = SLX1.SaleID
join #SaleLocationXREF SLX2
on S2.SaleID = SLX2.SaleID
and SLX1.LocationID = SLX2.LocationID -- Compare location overlap
) #SaleOverlap
on #SaleOverlap.SaleID = SIX.SaleID
) ItemOverlap
where ItemOverlap.Cnt > 1 -- Compare item overlap
OPTION (MAXDOP 1)
SET STATISTICS TIME OFF
drop table #SaleLocationXref
drop table #Sale
drop table #SaleItemXref
The interesting thing about this (at least to me) is the high degree of parallelism in your query. Note how CPU is greater than elapsed time for "Original query" below. I ran it also with OPTION (MAXDOP 1) to see what it would look like without parallelism. These results are here:
---- Revised query
SQL Server Execution Times:
CPU time = 2791 ms, elapsed time = 5481 ms.
---- Original query
SQL Server Execution Times:
CPU time = 3403 ms, elapsed time = 974 ms.
---- Original query with MAXDOP 1
SQL Server Execution Times:
CPU time = 1840 ms, elapsed time = 1883 ms.
My thought question: Have you ever been told that your query runs too fast?
My advice:
INDEXing a poor-performing query is like putting sugar on cat food. Yeah, it probably tastes better but are you sure you want to eat it?
The path of least resistance can be a slippery slope. Take care that fixing your fixes of fixes doesn't snowball and end up costing you more than fixing the root cause would have in the first place.
Need to UNPIVOT? Why not CROSS APPLY VALUES instead?[/url]
Since random numbers are too important to be left to chance, let's generate some![/url]
Learn to understand recursive CTEs by example.[/url]
[url url=http://www.sqlservercentral.com/articles/St
August 20, 2012 at 11:32 am
Dwain.c,
Thank you for all the effort you put into this.
I'm still searching for some way to limit the searching for common rows (common sale items or common sale locations) to just the first match, eliminating the need to have to compare all items/locations to determine that a pair of Sales have a common Item at a common Location at the same time (SaleStart/SaleEnd).
I'm finding that Celko's idea of using EXISTS (select f1.item_id INTERSECT select f2.item_id), can sometimes work better that I initially thought, so I'm currently experimenting more with that technique, but I'm still looking for some other good ideas if anyone has any.
I'm grateful to you all for helping me with ideas to solve this problem.
August 20, 2012 at 5:46 pm
The code below ran pretty fast on my desktop. Give it a try:
SELECT DISTINCT @holder1 = s1.SaleID,@holder2 = LocationID
FROM #Sale s1
INNER JOIN #SaleLocationXref SLX1 ON S1.SaleID = SLX1.SaleID
INNER JOIN #SaleItemXref SIX ON SIX.SaleID = s1.SaleID
WHERE EXISTS(
SELECT 1
FROM #Sale s2
INNER JOIN #SaleLocationXref SLX2 ON s2.SaleID = SLX2.SaleID
INNER JOIN #SaleItemXref SIX2 ON SIX2.SaleID = s2.SaleID
WHERE s1.SaleID <> s2.SaleID
AND s1.SaleStart <= s2.SaleEnd
AND s2.SaleStart <= s1.SaleEnd
AND SLX2.LocationID = SLX1.LocationID
AND SIX.ItemID = SIX2.ItemID)
GROUP BY s1.SaleID,LocationID
August 20, 2012 at 7:17 pm
SQL Padawan (8/20/2012)
The code below ran pretty fast on my desktop. Give it a try:
SELECT DISTINCT @holder1 = s1.SaleID,@holder2 = LocationIDFROM #Sale s1
INNER JOIN #SaleLocationXref SLX1 ON S1.SaleID = SLX1.SaleID
INNER JOIN #SaleItemXref SIX ON SIX.SaleID = s1.SaleID
WHERE EXISTS(
SELECT 1
FROM #Sale s2
INNER JOIN #SaleLocationXref SLX2 ON s2.SaleID = SLX2.SaleID
INNER JOIN #SaleItemXref SIX2 ON SIX2.SaleID = s2.SaleID
WHERE s1.SaleID <> s2.SaleID
AND s1.SaleStart <= s2.SaleEnd
AND s2.SaleStart <= s1.SaleEnd
AND SLX2.LocationID = SLX1.LocationID
AND SIX.ItemID = SIX2.ItemID)
GROUP BY s1.SaleID,LocationID
+1 SQL Padawan. The force was with you!
---- Original query
SQL Server Execution Times:
CPU time = 3433 ms, elapsed time = 942 ms.
---- Dwain's query
SQL Server Execution Times:
CPU time = 3230 ms, elapsed time = 1789 ms.
---- SQL Padawan
SQL Server Execution Times:
CPU time = 124 ms, elapsed time = 123 ms.
My thought question: Have you ever been told that your query runs too fast?
My advice:
INDEXing a poor-performing query is like putting sugar on cat food. Yeah, it probably tastes better but are you sure you want to eat it?
The path of least resistance can be a slippery slope. Take care that fixing your fixes of fixes doesn't snowball and end up costing you more than fixing the root cause would have in the first place.
Need to UNPIVOT? Why not CROSS APPLY VALUES instead?[/url]
Since random numbers are too important to be left to chance, let's generate some![/url]
Learn to understand recursive CTEs by example.[/url]
[url url=http://www.sqlservercentral.com/articles/St
August 21, 2012 at 7:39 am
^^^ lol. I need to change the moniker.
Here is a revised version eliminating the GROUP BY and/or DISTINCT clauses. I especially dislike using either of those to return non-aggregated data. Most of the time there is always a better and more efficient way to write the query.
SELECT s1.SaleID,LocationID
FROM #Sale s1
INNER JOIN #SaleLocationXref SLX1 ON S1.SaleID = SLX1.SaleID --Find location
WHERE EXISTS(
SELECT 1
FROM #Sale s2
INNER JOIN #SaleLocationXref SLX2 ON s2.SaleID = SLX2.SaleID --Find location
INNER JOIN #SaleItemXref SIX2 ON SIX2.SaleID = s2.SaleID --Find item
WHERE s1.SaleID <> s2.SaleID --Make sure that we are comparing two different SaleIDs
AND s1.SaleStart <= s2.SaleEnd --Make sure that they fall within date ranges of each other
AND s2.SaleStart <= s1.SaleEnd --^^
AND SLX2.LocationID = SLX1.LocationID --Where s1 and s2 have the same location id
AND EXISTS(
SELECT 1
FROM #SaleItemXref SIX
WHERE SIX.SaleID = s1.SaleID --Find sale item for record s1
AND SIX.ItemID = SIX2.ItemID --Make sure sale item from s1 has a matching record in s2
)
)
August 21, 2012 at 9:03 am
Sales 1 and 2 overlap on date range and have a common item & location.
Same with 2 and 5. But 1 and 5 don't overlap: 1, 2 & 5 aren't a set with overlapping date ranges and location in common.
It makes more sense to me to do this as sales pairs, as follows:
SELECT
s1_SaleID = s1.SaleID,
s2_SaleID = s2.SaleID,
l.*, i.*
FROM Sale s1
INNER JOIN Sale s2
ON s1.SaleID < s2.SaleID
AND S1.SaleStart <= S2.SaleEnd
AND S2.SaleStart <= S1.SaleEnd
CROSS APPLY (
SELECT li.LocationID
FROM SaleLocationXref li
WHERE li.SaleID = s1.SaleID
OR li.SaleID = s2.SaleID
GROUP BY li.LocationID
HAVING COUNT(*) = 2
) l
CROSS APPLY (
SELECT ii.ItemID
FROM SaleItemXref ii
WHERE ii.SaleID = s1.SaleID
OR ii.SaleID = s2.SaleID
GROUP BY ii.ItemID
HAVING COUNT(*) = 2
) i
For fast, accurate and documented assistance in answering your questions, please read this article.
Understanding and using APPLY, (I) and (II) Paul White
Hidden RBAR: Triangular Joins / The "Numbers" or "Tally" Table: What it is and how it replaces a loop Jeff Moden
August 21, 2012 at 11:54 am
Here is another potential solution. Would like to have others give it a test.
Against the small original test set it worked. Unfortunately, I think it may be wrong in other ways. This would probably work better if there were a fixed test suite of values with a validated results set to test against.
with BaseData as (
select
s.SaleID,
s.SaleStart,
s.SaleEnd,
slx.LocationID,
six.ItemID
from
Sale s
inner join SaleLocationXref slx
on (s.SaleID = slx.SaleID)
inner join SaleItemXref six
on (s.SaleID = six.SaleID)
)
select
bd.SaleID,
bd.SaleStart,
bd.SaleEnd,
bd.LocationID,
bd.ItemID
from
BaseData bd
where
exists(select 1
from BaseData bd1
where
bd.SaleID <> bd1.SaleID and
bd.LocationID = bd1.LocationID and
bd.ItemID = bd1.ItemID and
bd.SaleStart <= bd1.SaleEnd and
bd.SaleEnd >= bd1.SaleStart)
order by
bd.ItemID,
bd.LocationID,
bd.SaleID;
Modified to work using the test suite above (I commented 3 lines in the final select statement and added the holder variables) and include a run using MAXDOP(1) as well:
set nocount on;
go
create table #SaleLocationXref (
SaleID int not null,
LocationID int not null,
constraint SaleLocationXref_PK primary key (SaleID,LocationID)
)
create table #Sale (
SaleID int not null,
SaleStart datetime not null,
SaleEnd datetime not null,
constraint Sale_PK primary key (SaleID)
)
create table #SaleItemXref (
SaleID int not null,
ItemID int not null,
constraint SaleItemXref_PK primary key (SaleID,ItemID)
)
insert into #SaleLocationXref values (1,1),(2,1),(4,1),(5,1),
(3,2)
insert into #Sale values (1,'01/01/2012','01/07/2012'),
(2,'01/06/2012','01/10/2012'),
(3,'01/01/2012','02/07/2012'),
(4,'02/08/2012','02/15/2012'),
(5,'01/09/2012','01/16/2012')
insert into #SaleItemXref values (1,1),(1,2),(1,3),
(2,1),(2,4),(2,5),
(3,5),(3,6),(3,7),
(4,5),(4,6),(4,7),
(5,7),(5,8),(5,1)
;WITH Tally (n) AS (
SELECT TOP 10000 10+ROW_NUMBER() OVER (ORDER BY (SELECT NULL))
FROM sys.all_columns t1 CROSS JOIN sys.all_columns t2)
INSERT INTO #SaleLocationXref
SELECT DISTINCT SaleID * n, LocationID * n
FROM #SaleLocationXref
CROSS APPLY Tally
;WITH Tally (n) AS (
SELECT TOP 10000 10+ROW_NUMBER() OVER (ORDER BY (SELECT NULL))
FROM sys.all_columns t1 CROSS JOIN sys.all_columns t2)
INSERT INTO #Sale
SELECT SaleID, SaleStart, SaleEnd
FROM (
SELECT SaleID=SaleID * n, SaleStart, SaleEnd
,n=ROW_NUMBER() OVER (PARTITION BY SaleID * n ORDER BY (SELECT NULL))
FROM #Sale
CROSS APPLY Tally) a
WHERE n = 1
;WITH Tally (n) AS (
SELECT TOP 10000 10+ROW_NUMBER() OVER (ORDER BY (SELECT NULL))
FROM sys.all_columns t1 CROSS JOIN sys.all_columns t2)
INSERT INTO #SaleItemXref
SELECT DISTINCT SaleID * n, ItemID * n
FROM #SaleItemXref
CROSS APPLY Tally
DECLARE @Holder1 INT, @Holder2 INT
PRINT '';
PRINT '---- Revised query'
SET STATISTICS TIME ON
;WITH Sale AS (
SELECT a.SaleID, a.SaleStart, a.SaleEnd, b.LocationID, c.ItemID
FROM #Sale a
JOIN #SaleLocationXref b ON a.SaleID = b.SaleID
JOIN #SaleItemXref c ON c.SaleID = a.SaleID
)
SELECT @Holder1=SaleID, @Holder2=LocationID
FROM (
SELECT a.SaleID, a.SaleStart, a.SaleEnd, a.LocationID, a.ItemID
, SaleID2=b.SaleID, LocationID2=b.LocationID, ItemID2=b.ItemID
,n=ROW_NUMBER() OVER (PARTITION BY a.SaleID, a.LocationID ORDER BY (SELECT NULL))
FROM Sale a
CROSS APPLY (
SELECT SaleID, LocationID, ItemID
FROM Sale b
WHERE (b.SaleStart BETWEEN a.SaleStart AND b.SaleEnd OR
b.SaleEnd BETWEEN a.SaleStart AND b.SaleEnd) AND a.SaleID <> b.SaleID) b
WHERE a.LocationID = b.LocationID AND a.ItemID = b.ItemID) c
WHERE n=1
SET STATISTICS TIME OFF
PRINT '';
PRINT '---- Original query'
SET STATISTICS TIME ON
select distinct @Holder1=SaleID, @Holder2=LocationID
from (
select SIX.SaleID, LocationID, ItemID,
Count(*) over (partition by LocationID, ItemID) as Cnt
from #SaleItemXref SIX
join (
select distinct S1.SaleID, SLX1.LocationID
from #Sale S1
join #Sale S2 -- Compare sales
on S1.SaleID <> S2.SaleID
and (S1.SaleStart <= S2.SaleEnd -- Compare dates overlap
and S2.SaleStart <= S1.SaleEnd)
join #SaleLocationXref SLX1
on S1.SaleID = SLX1.SaleID
join #SaleLocationXREF SLX2
on S2.SaleID = SLX2.SaleID
and SLX1.LocationID = SLX2.LocationID -- Compare location overlap
) #SaleOverlap
on #SaleOverlap.SaleID = SIX.SaleID
) ItemOverlap
where ItemOverlap.Cnt > 1 -- Compare item overlap
SET STATISTICS TIME OFF
PRINT '';
PRINT '---- Original query with MAXDOP 1'
SET STATISTICS TIME ON
select distinct @Holder1=SaleID, @Holder2=LocationID
from (
select SIX.SaleID, LocationID, ItemID,
Count(*) over (partition by LocationID, ItemID) as Cnt
from #SaleItemXref SIX
join (
select distinct S1.SaleID, SLX1.LocationID
from #Sale S1
join #Sale S2 -- Compare sales
on S1.SaleID <> S2.SaleID
and (S1.SaleStart <= S2.SaleEnd -- Compare dates overlap
and S2.SaleStart <= S1.SaleEnd)
join #SaleLocationXref SLX1
on S1.SaleID = SLX1.SaleID
join #SaleLocationXREF SLX2
on S2.SaleID = SLX2.SaleID
and SLX1.LocationID = SLX2.LocationID -- Compare location overlap
) #SaleOverlap
on #SaleOverlap.SaleID = SIX.SaleID
) ItemOverlap
where ItemOverlap.Cnt > 1 -- Compare item overlap
OPTION (MAXDOP 1)
SET STATISTICS TIME OFF
PRINT '';
PRINT '---- Lynn''s Query';
SET STATISTICS TIME ON;
with BaseData as (
select
s.SaleID,
s.SaleStart,
s.SaleEnd,
slx.LocationID,
six.ItemID
from
#Sale s
inner join #SaleLocationXref slx
on (s.SaleID = slx.SaleID)
inner join #SaleItemXref six
on (s.SaleID = six.SaleID)
)
select
--bd.SaleStart,
--bd.SaleEnd,
--bd.ItemID,
@Holder1 = bd.SaleID,
@Holder2 = bd.LocationID
from
BaseData bd
where
exists(select 1
from BaseData bd1
where
bd.SaleID <> bd1.SaleID and
bd.LocationID = bd1.LocationID and
bd.ItemID = bd1.ItemID and
bd.SaleStart <= bd1.SaleEnd and
bd.SaleEnd >= bd1.SaleStart)
order by
bd.ItemID,
bd.LocationID,
bd.SaleID
;
SET STATISTICS TIME OFF
PRINT '';
PRINT '---- Lynn''s Query with MAXDOP(1)';
SET STATISTICS TIME ON;
with BaseData as (
select
s.SaleID,
s.SaleStart,
s.SaleEnd,
slx.LocationID,
six.ItemID
from
#Sale s
inner join #SaleLocationXref slx
on (s.SaleID = slx.SaleID)
inner join #SaleItemXref six
on (s.SaleID = six.SaleID)
)
select
--bd.SaleStart,
--bd.SaleEnd,
--bd.ItemID,
@Holder1 = bd.SaleID,
@Holder2 = bd.LocationID
from
BaseData bd
where
exists(select 1
from BaseData bd1
where
bd.SaleID <> bd1.SaleID and
bd.LocationID = bd1.LocationID and
bd.ItemID = bd1.ItemID and
bd.SaleStart <= bd1.SaleEnd and
bd.SaleEnd >= bd1.SaleStart)
order by
bd.ItemID,
bd.LocationID,
bd.SaleID
OPTION (MAXDOP 1);
SET STATISTICS TIME OFF
go
drop table #SaleLocationXref
drop table #Sale
drop table #SaleItemXref
And the results when run on a test VM:
---- Revised query
SQL Server Execution Times:
CPU time = 2768 ms, elapsed time = 1646 ms.
---- Original query
SQL Server Execution Times:
CPU time = 2609 ms, elapsed time = 1372 ms.
---- Original query with MAXDOP 1
SQL Server Execution Times:
CPU time = 2312 ms, elapsed time = 2337 ms.
---- Lynn's Query
SQL Server Execution Times:
CPU time = 1141 ms, elapsed time = 641 ms.
---- Lynn's Query with MAXDOP(1)
SQL Server Execution Times:
CPU time = 969 ms, elapsed time = 969 ms.
August 21, 2012 at 5:20 pm
I want to express my sincere gratitude to all of you for the valuable help you have offered me here.
Thanks to your help, I have a solution now that I think is going to work for me. There is something that still puzzles me related to this problem and my solution to it, but I need a little time to boil that down into a reasonably specific question. If I end up posting a new question relating to this problem, I'll add a reference to it on this thread in case anyone of you might be interested.
Thank you all for your contributions.
The DDL that I gave originally doesn't match my actual DDL, it was only meant to represent a subset of the query problem I faced. The solution I have settled on for now as applied to the DDL in my original post would look like this:
-- Sales that overlap on effective dates
select distinct S1.SaleID, S2.SaleID OverlapSaleID
into #SO
from Sale S1
join Sale S2 -- Compare sales
on S1.SaleID <> S2.SaleID
and (S1.SaleStart <= S2.SaleEnd -- Compare dates overlap
and S2.SaleStart <= S1.SaleEnd)
intersect
-- Sales that overlap on Location
select distinct SLX1.SaleID, SLX2.SaleID OverlapSaleID
from SaleLocationXref SLX1
join SaleLocationXREF SLX2
on SLX1.SaleID <> SLX2.SaleID
-- and SLX1.LocationID = SLX2.LocationID
where EXISTS(select SLX1.LocationID INTERSECT select SLX2.LocationID)
;with SOIO as (
select distinct #SO.SaleID, #SO.OverlapSaleID
from #SO
join SaleItemXref SIX1
on #SO.SaleID = SIX1.SaleID
join SaleItemXref SIX2
on #SO.OverlapSaleID = SIX2.SaleID
-- and SIX1.ItemID = SIX2.ItemID
where EXISTS(select SIX1.ItemID intersect select SIX2.ItemID)
)
select distinct SaleID, Count(OverlapSaleID) OVERLAP_CNT -- OverlapSaleID
from SOIO
group by SaleID
order by SaleID;
As ChrisM@Work pointed out, it was more useful to know that 1 overlaped with 2 and 2 overlapped with 5 that it was to know that 1, 2 and 5 were all involved in an overlap. So, I change the schema of the result set returned in the solution above from my original post.
A couple of other notes about the solution:
1) I ended up storing intermediate results into a #SO temp table instead of including it as a named result set in the final query, because the query optimizer created a much more performant execution plan with the use of the temp table (I don't understand why).
2) When comparing overlapping LocationID and ItemID, using a join seemed to produce the same query plan and execution times as using the EXISTS(...intersect...) technique in the where clause. I believe that the EXISTS (...intersect...) technique should have been able to deliver better performance than it actually does, so I'm going to go with it and hope to pickup some performance in future updates to SQL Server.
August 21, 2012 at 11:47 pm
aostanley (8/21/2012)
I want to express my sincere gratitude to all of you for the valuable help you have offered me here.Thanks to your help, I have a solution now that I think is going to work for me. There is something that still puzzles me related to this problem and my solution to it, but I need a little time to boil that down into a reasonably specific question. If I end up posting a new question relating to this problem, I'll add a reference to it on this thread in case anyone of you might be interested.
Thank you all for your contributions.
The DDL that I gave originally doesn't match my actual DDL, it was only meant to represent a subset of the query problem I faced. The solution I have settled on for now as applied to the DDL in my original post would look like this:
-- Sales that overlap on effective dates
select distinct S1.SaleID, S2.SaleID OverlapSaleID
into #SO
from Sale S1
join Sale S2 -- Compare sales
on S1.SaleID <> S2.SaleID
and (S1.SaleStart <= S2.SaleEnd -- Compare dates overlap
and S2.SaleStart <= S1.SaleEnd)
intersect
-- Sales that overlap on Location
select distinct SLX1.SaleID, SLX2.SaleID OverlapSaleID
from SaleLocationXref SLX1
join SaleLocationXREF SLX2
on SLX1.SaleID <> SLX2.SaleID
-- and SLX1.LocationID = SLX2.LocationID
where EXISTS(select SLX1.LocationID INTERSECT select SLX2.LocationID)
;with SOIO as (
select distinct #SO.SaleID, #SO.OverlapSaleID
from #SO
join SaleItemXref SIX1
on #SO.SaleID = SIX1.SaleID
join SaleItemXref SIX2
on #SO.OverlapSaleID = SIX2.SaleID
-- and SIX1.ItemID = SIX2.ItemID
where EXISTS(select SIX1.ItemID intersect select SIX2.ItemID)
)
select distinct SaleID, Count(OverlapSaleID) OVERLAP_CNT -- OverlapSaleID
from SOIO
group by SaleID
order by SaleID;
As ChrisM@Work pointed out, it was more useful to know that 1 overlaped with 2 and 2 overlapped with 5 that it was to know that 1, 2 and 5 were all involved in an overlap. So, I change the schema of the result set returned in the solution above from my original post.
A couple of other notes about the solution:
1) I ended up storing intermediate results into a #SO temp table instead of including it as a named result set in the final query, because the query optimizer created a much more performant execution plan with the use of the temp table (I don't understand why).
2) When comparing overlapping LocationID and ItemID, using a join seemed to produce the same query plan and execution times as using the EXISTS(...intersect...) technique in the where clause. I believe that the EXISTS (...intersect...) technique should have been able to deliver better performance than it actually does, so I'm going to go with it and hope to pickup some performance in future updates to SQL Server.
I'm glad you have a solution, but I think you may be missing a different solution.
You should take a close look at the execution plans for each of the solutions provided below (in the attached zip file). You should try downloading SQL Sentry's Plan Explorer and compare the options. You may be surprised at what you find.
The attached file has the code for setting up the tables, updated code that can be run from SQL Sentry's Plan Explorer after setting up the tables.
I have also included the sqlplans from Plan Explorer.
These sqlplans can also be opened and viewed in SSMS.
September 18, 2012 at 3:08 am
Removed: Didn't test properly.
N 56°04'39.16"
E 12°55'05.25"
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