I'm trying to using the aggregation features of the django ORM to run a query on a MSSQL 2008R2 database, but I keep getting a timeout error. The query (generated by django) which fails is below. I've tried running it directs the SQL management studio and it works, but takes 3.5 min
It does look it's aggregating over a bunch of fields which it doesn't need to, but I wouldn't have though that should really cause it to take that long. The database isn't that big either, auth_user has 9 records, ticket_ticket has 1210, and ticket_watchers has 1876. Is there something I'm missing?
SELECT
[auth_user].[id],
[auth_user].[password],
[auth_user].[last_login],
[auth_user].[is_superuser],
[auth_user].[username],
[auth_user].[first_name],
[auth_user].[last_name],
[auth_user].[email],
[auth_user].[is_staff],
[auth_user].[is_active],
[auth_user].[date_joined],
COUNT([tickets_ticket].[id]) AS [tickets_captured__count],
COUNT(T3.[id]) AS [assigned_tickets__count],
COUNT([tickets_ticket_watchers].[ticket_id]) AS [tickets_watched__count]
FROM
[auth_user]
LEFT OUTER JOIN [tickets_ticket] ON ([auth_user].[id] = [tickets_ticket].[capturer_id])
LEFT OUTER JOIN [tickets_ticket] T3 ON ([auth_user].[id] = T3.[responsible_id])
LEFT OUTER JOIN [tickets_ticket_watchers] ON ([auth_user].[id] = [tickets_ticket_watchers].[user_id])
GROUP BY
[auth_user].[id],
[auth_user].[password],
[auth_user].[last_login],
[auth_user].[is_superuser],
[auth_user].[username],
[auth_user].[first_name],
[auth_user].[last_name],
[auth_user].[email],
[auth_user].[is_staff],
[auth_user].[is_active],
[auth_user].[date_joined]
HAVING
(COUNT([tickets_ticket].[id]) > 0 OR COUNT(T3.[id]) > 0 )
EDIT:
Here are the relevant indexes (excluding those not used in the query):
auth_user.id (PK)
auth_user.username (Unique)
tickets_ticket.id (PK)
tickets_ticket.capturer_id
tickets_ticket.responsible_id
tickets_ticket_watchers.id (PK)
tickets_ticket_watchers.user_id
tickets_ticket_watchers.ticket_id
EDIT 2:
After a bit of experimentation, I've found that the following query is the smallest that results in the slow execution:
SELECT
COUNT([tickets_ticket].[id]) AS [tickets_captured__count],
COUNT(T3.[id]) AS [assigned_tickets__count],
COUNT([tickets_ticket_watchers].[ticket_id]) AS [tickets_watched__count]
FROM
[auth_user]
LEFT OUTER JOIN [tickets_ticket] ON ([auth_user].[id] = [tickets_ticket].[capturer_id])
LEFT OUTER JOIN [tickets_ticket] T3 ON ([auth_user].[id] = T3.[responsible_id])
LEFT OUTER JOIN [tickets_ticket_watchers] ON ([auth_user].[id] = [tickets_ticket_watchers].[user_id])
GROUP BY
[auth_user].[id]
The weird thing is that if I comment out any two lines in the above, it runs in less that 1s, but it doesn't seem to matter which lines I remove (although obviously I can't remove a join without also removing the relevant SELECT line).
EDIT 3:
The python code which generated this is:
User.objects.annotate(
Count('tickets_captured'),
Count('assigned_tickets'),
Count('tickets_watched')
)
A look at the execution plan shows that SQL Server is first doing a cross-join on all the table, resulting in about 280 million rows, and 6Gb of data. I assume that this is where the problem lies, but why is it happening?
SQL Server is doing exactly what it was asked to do. Unfortunately, Django is not generating the right query for what you want. It looks like you need to count distinct, instead of just count: Django annotate() multiple times causes wrong answers
As for why the query works that way: The query says to join the four tables together. So say an author has 2 captured tickets, 3 assigned tickets, and 4 watched tickets, the join will return 2*3*4 tickets, one for each combination of tickets. The distinct part will remove all the duplicates.
what about this?
SELECT auth_user.*,
C1.tickets_captured__count
C2.assigned_tickets__count
C3.tickets_watched__count
FROM
auth_user
LEFT JOIN
( SELECT capturer_id, COUNT(*) AS tickets_captured__count
FROM tickets_ticket GROUP BY capturer_id ) AS C1 ON auth_user.id = C1.capturer_id
LEFT JOIN
( SELECT responsible_id, COUNT(*) AS assigned_tickets__count
FROM tickets_ticket GROUP BY responsible_id ) AS C2 ON auth_user.id = C2.responsible_id
LEFT JOIN
( SELECT user_id, COUNT(*) AS tickets_watched__count
FROM tickets_ticket_watchers GROUP BY user_id ) AS C3 ON auth_user.id = C3.user_id
WHERE C1.tickets_captured__count > 0 OR C2.assigned_tickets__count > 0
--WHERE C1.tickets_captured__count is not null OR C2.assigned_tickets__count is not null -- also works (I think with beter performance)
Related
I have a table that is for PaymentRequest (PR), each PR table has two forms of pay, a WorkProgress, and a AdvanceByWarranty, the relation is like this:
I Need to create a report to get all the payment made in that (PR), and some other fields between them
The sql that I was using to join PaymentRequest with WorkProgress is this, and it works, it returns the WorkProgress of that payment
To get the Advances by warranty I use this, it also works, returns 2 Advances, as it should be
But, when I mix both, it doesnt return 3 rows, as it should be, it returns two. The result is this
I was expecting something like this (With shorter names)
How can i get the expected query?
Edit:
The sql to get the expected query is this
select
pr.ProjectId, pr.NumberPaymentState,
wp.ToCollectAmmount as WPAmmount, wp.ToCollectPercent as WPPercent,
null as AWAmmount, null as AWPercent
from PaymentRequests pr
left join WorkProgresses wp on (wp.ProjectId = pr.ProjectId and wp.NumberPaymentState = pr.NumberPaymentState)
union all
select
pr.ProjectId, pr.NumberPaymentState,
null as WPAmmount, null as WPPercent,
aw.ToCollectAmmount as AWAmmount, aw.ToCollectPercent as AWPercent
from PaymentRequests pr
left join AdvanceByWarranties aw on (aw.ProjectId = pr.ProjectId and aw.NumberPaymentState = pr.NumberPaymentState)
You might have wanted what you show, but it doesn't work like this.
Just use UNION ALL between your first two queries, and rename the columns accordingly. Here is some pseudocode hybrid to guide you:
select keycols, workercols, null as advancecols
from pr join worker
union all
select keycols, null as workercols, advancecols
from pr join advancecols
I'm trying to join 4 tables that have a somewhat complex relationship. Because of where this will be used, it needs to be contained in a single query, but I'm having trouble since the primary query and the IN clause query both join 2 tables together and the lookup is on two columns.
The goal is to input a SalesNum and SalesType and have it return the Price
Tables and relationships:
sdShipping
SalesNum[1]
SalesType[2]
Weight[3]
sdSales
SalesNum[1]
SalesType[2]
Zip[4]
spZones
Zip[4]
Zone[5]
spPrices
Zone[5]
Price
Weight[3]
Here's my latest attempt in T-SQL:
SELECT
spp.Price
FROM
spZones AS spz
LEFT OUTER JOIN
spPrices AS spp ON spz.Zone = spp.Zone
WHERE
(spp.Weight, spz.Zip) IN (SELECT ship.Weight, sales.Zip
FROM sdShipping AS ship
LEFT OUTER JOIN sdSales AS sales ON sales.SalesNum = ship.SalesNum
AND sales.SalesType = ship.SalesType
WHERE sales.SalesNum = (?)
AND ship.SalesType = (?));
SQL Server Management Studio says I have an error in my syntax near ',' (appropriately useless error message). Does anybody have any idea whether this is even allowed in Microsoft's version of SQL? Is there perhaps another way to accomplish it? I've seen the multi-key IN questions answered on here, but never in the case where both sides require a JOIN.
Many databases do support IN on tuples. SQL Server is not one of them.
Use EXISTS instead:
SELECT spp.Price
FROM spZones spz LEFT OUTER JOIN
spPrices spp
ON spz.Zone = spp.Zone
WHERE EXISTS (SELECT 1
FROM sdShipping ship LEFT JOIN
sdSales sales
ON sales.SalesNum = ship.SalesNum AND
sales.SalesType = ship.SalesType
WHERE spp.Weight = ship.Weight AND spz.Zip = sales.Zip AND
sales.SalesNum = (?) AND
ship.SalesType = (?)
);
I made a query and wanted to not have any duplicates but i got some times 3 duplicates and when i used DISTINCT or DISTINCTROW i got only 2 duplicates.
SELECT f.flight_code,
f.status,
a.airport_name,
a1.airport_name,
f.departing_date+f.departing_time AS SupposedDepartingTime,
f.landing_date+f.landing_time AS SupposedLandingTime,
de.actual_takeoff_date+de.actual_takeoff_time AS ActualDepartingTime,
SupposedLandingTime+(ActualDepartingTime-SupposedDepartingTime) AS ActualLandingTime
FROM
(((Flights AS f
LEFT JOIN Aireports AS a
ON a.airport_code = f.depart_ap)
LEFT JOIN Aireports AS a1
ON f.target_ap = a1.airport_code)
LEFT JOIN Irregular_Events AS ie
ON f.flight_code = ie.flight_code)
LEFT JOIN Delay_Event AS de
ON ie.IE_code = de.delay_code;
had to use LEFT JOIN because when i used INNER JOIN i missed some of the things i wanted to show because i wanted to see all the flights and not only the flights that got delayed or canceled.
This is the results when i used INNER JOIN, you can see only the flights that have the status "ביטול" or "עיכוב" and that is not what i wanted.
[the results with LEFT JOIN][2]
[2]: https://i.stack.imgur.com/cgE2G.png
and when i used DISTINCT where you see the rows with the NUMBER 6 on the first column it appear only two times
IMPORTANT!
I just checked my query and all the tables i use there and i saw my problem but dont know how to fix it!
in the table Irregular_Events i have more the one event for flights 3,6 and 8 and that is why when i use LEFT JOIN i see more even thou i use distinct, please give me some help!
Not entirely sure without seeing the table structure, but this might work:
SELECT f.flight_code,
f.status,
a.airport_name,
a1.airport_name,
f.departing_date+f.departing_time AS SupposedDepartingTime,
f.landing_date+f.landing_time AS SupposedLandingTime,
de.actual_takeoff_date+de.actual_takeoff_time AS ActualDepartingTime,
SupposedLandingTime+(ActualDepartingTime-SupposedDepartingTime) AS ActualLandingTime
FROM
((Flights AS f
LEFT JOIN Aireports AS a
ON a.airport_code = f.depart_ap)
LEFT JOIN Aireports AS a1
ON f.target_ap = a1.airport_code)
LEFT JOIN
(
SELECT
ie.flight_code,
de1.actual_takeoff_date,
de1.actual_takeoff_time
FROM
Irregular_Events ie
INNER JOIN Event AS de1
ON ie.IE_code = de1.delay_code
) AS de
ON f.flight_code = de.flight_code
It is hard to tell what is the problem with your query without any sample of the output, and without any description of the structure of your tables.
But your problem is that your are querying from the flights table, which [I assume] can be linked to multiple irregular_events, which can possibly also be linked to multiple delay_event.
If you want to get only one row per flight, you need to make sure your joins return only one row too. Maybe you can do it by adding one more condition to the join, or by adding a condition in a sub-query.
EDIT
You could try to add a GROUP BY to the query:
GROUP BY
f.flight_code,
f.status,
a.airport_name,
a1.airport_name;
I am having a problem with my SQL query using the count function.
When I don't have an inner join, it counts 55 rows. When I add the inner join into my query, it adds a lot to it. It suddenly became 102 rows.
Here is my SQL Query:
SELECT COUNT([fmsStage].[dbo].[File].[FILENUMBER])
FROM [fmsStage].[dbo].[File]
INNER JOIN [fmsStage].[dbo].[Container]
ON [fmsStage].[dbo].[File].[FILENUMBER] = [fmsStage].[dbo].[Container].[FILENUMBER]
WHERE [fmsStage].[dbo].[File].[RELATIONCODE] = 'SHIP02'
AND [fmsStage].[dbo].[Container].DELIVERYDATE BETWEEN '2016-10-06' AND '2016-10-08'
GROUP BY [fmsStage].[dbo].[File].[FILENUMBER]
Also, I have to do TOP 1 at the SELECT statement because it returns 51 rows with random numbers inside of them. (They are probably not random, but I can't figure out what they are.)
What do I have to do to make it just count the rows from [fmsStage].[dbo].[file].[FILENUMBER]?
First, your query would be much clearer like this:
SELECT COUNT(f.[FILENUMBER])
FROM [fmsStage].[dbo].[File] f INNER JOIN
[fmsStage].[dbo].[Container] c
ON v.[FILENUMBER] = c.[FILENUMBER]
WHERE f.[RELATIONCODE] = 'SHIP02' AND
c.DELIVERYDATE BETWEEN '2016-10-06' AND '2016-10-08';
No GROUP BY is necessary. Otherwise you'll just one row per file number, which doesn't seem as useful as the overall count.
Note: You might want COUNT(DISTINCT f.[FILENUMBER]). Your question doesn't provide enough information to make a judgement.
Just remove GROUP BY Clause
SELECT COUNT([fmsStage].[dbo].[File].[FILENUMBER])
FROM [fmsStage].[dbo].[File]
INNER JOIN [fmsStage].[dbo].[Container]
ON [fmsStage].[dbo].[File].[FILENUMBER] = [fmsStage].[dbo].[Container].[FILENUMBER]
WHERE [fmsStage].[dbo].[File].[RELATIONCODE] = 'SHIP02'
AND [fmsStage].[dbo].[Container].DELIVERYDATE BETWEEN '2016-10-06' AND '2016-10-08'
I have a SQL query with many left joins
SELECT COUNT(DISTINCT po.o_id)
FROM T_PROPOSAL_INFO po
LEFT JOIN T_PLAN_TYPE tp ON tp.plan_type_id = po.Plan_Type_Fk
LEFT JOIN T_PRODUCT_TYPE pt ON pt.PRODUCT_TYPE_ID = po.cust_product_type_fk
LEFT JOIN T_PROPOSAL_TYPE prt ON prt.PROPTYPE_ID = po.proposal_type_fk
LEFT JOIN T_BUSINESS_SOURCE bs ON bs.BUSINESS_SOURCE_ID = po.CONT_AGT_BRK_CHANNEL_FK
LEFT JOIN T_USER ur ON ur.Id = po.user_id_fk
LEFT JOIN T_ROLES ro ON ur.roleid_fk = ro.Role_Id
LEFT JOIN T_UNDERWRITING_DECISION und ON und.O_Id = po.decision_id_fk
LEFT JOIN T_STATUS st ON st.STATUS_ID = po.piv_uw_status_fk
LEFT OUTER JOIN T_MEMBER_INFO mi ON mi.proposal_info_fk = po.O_ID
WHERE 1 = 1
AND po.CUST_APP_NO LIKE '%100010233976%'
AND 1 = 1
AND po.IS_STP <> 1
AND po.PIV_UW_STATUS_FK != 10
The performance seems to be not good and I would like to optimize the query.
Any suggestions please?
Try this one -
SELECT COUNT(DISTINCT po.o_id)
FROM T_PROPOSAL_INFO po
WHERE PO.CUST_APP_NO LIKE '%100010233976%'
AND PO.IS_STP <> 1
AND po.PIV_UW_STATUS_FK != 10
First, check your indexes. Are they old? Did they get fragmented? Do they need rebuilding?
Then, check your "execution plan" (varies depending on the SQL Engine): are all joins properly understood? Are some of them 'out of order'? Do some of them transfer too many data?
Then, check your plan and indexes: are all important columns covered? Are there any outstandingly lengthy table scans or joins? Are the columns in indexes IN ORDER with the query?
Then, revise your query:
- can you extract some parts that normally would quickly generate small rowset?
- can you add new columns to indexes so join/filter expressions will get covered?
- or reorder them so they match the query better?
And, supporting the solution from #Devart:
Can you eliminate some tables on the way? does the where touch the other tables at all? does the data in the other tables modify the count significantly? If neither SELECT nor WHERE never touches the other joined columns, and if the COUNT exact value is not that important (i.e. does that T_PROPOSAL_INFO exist?) then you might remove all the joins completely, as Devart suggested. LEFTJOINs never reduce the number of rows. They only copy/expand/multiply the rows.