Sql Optimization on advertising system - sql

Question

I am currently developing on an advertising system, which have been running just fine for a while now, apart from recently when our views per day have shot up from about 7k to 328k. Our server cannot take the pressure on this anymore - and knowing that I am not the best SQL guy around (hey, I can make it work, but not always in the best way) I am asking here for some optimization guidelines. I hope that some of you will be able to give rough ideas on how to improve this - I don't specifically need code, just to see the light :).
As it is at the moment, when an advert is supposed to be shown a PHP script is called, which in return calls a stored procedure. This stored procedure does several checks, it tests up against our customer database to see if the person showing the advert (given by a primary key id) is an actual customer under the given locale (our system is running on several languages which are all run as separate sites). Next up is all the advert details fetched out (image location as an url, height and width of the advert) - and lest step calls a separate stored procedure to test if the advert is allowed to be shown (is the campaign expired by either date or number of adverts allowed to show?) and if the customer has access to it (we got 2 access systems running, a blacklist and a whitelist one) and lastly what type of campaign we're running, is the view unique and so forth.
The code consists of a couple of stored procedures that I will post in here.
--- procedure called from PHP
CREATE PROCEDURE [dbo].[ExecView]
(
#publisherId bigint,
#advertId bigint,
#localeId int,
#ip varchar(15),
#ipIsUnique bit,
#success bit OUTPUT,
#campaignId bigint OUTPUT,
#advert varchar(500) OUTPUT,
#advertWidth int OUTPUT,
#advertHeight int OUTPUT
)
AS
BEGIN
SET NOCOUNT ON;
DECLARE #unique bit
DECLARE #approved bit
DECLARE #publisherEarning money
DECLARE #advertiserCost money
DECLARE #originalStatus smallint
DECLARE #advertUrl varchar(500)
DECLARE #return int
SELECT #success = 1, #advert = NULL, #advertHeight = NULL, #advertWidth = NULL
--- Must be valid publisher, ie exist and actually be a publisher
IF dbo.IsValidPublisher(#publisherId, #localeId) = 0
BEGIN
SELECT #success = 0
RETURN 0
END
--- Must be a valid advert
EXEC #return = FetchAdvertDetails #advertId, #localeId, #advert OUTPUT, #advertUrl OUTPUT, #advertWidth OUTPUT, #advertHeight OUTPUT
IF #return = 0
BEGIN
SELECT #success = 0
RETURN 0
END
EXEC CanAddStatToAdvert 2, #advertId, #publisherId, #ip, #ipIsUnique, #success OUTPUT, #unique OUTPUT, #approved OUTPUT, #publisherEarning OUTPUT, #advertiserCost OUTPUT, #originalStatus OUTPUT, #campaignId OUTPUT
IF #success = 1
BEGIN
INSERT INTO dbo.Stat (AdvertId, [Date], Ip, [Type], PublisherEarning, AdvertiserCost, [Unique], Approved, PublisherCustomerId, OriginalStatus)
VALUES (#advertId, GETDATE(), #ip, 2, #publisherEarning, #advertiserCost, #unique, #approved, #publisherId, #originalStatus)
END
END
--- IsValidPublisher
CREATE FUNCTION [dbo].[IsValidPublisher]
(
#publisherId bigint,
#localeId int
)
RETURNS bit
AS
BEGIN
DECLARE #customerType smallint
DECLARE #result bit
SET #customerType = (SELECT [Type] FROM dbo.Customer
WHERE CustomerId = #publisherId AND Deleted = 0 AND IsApproved = 1 AND IsBlocked = 0 AND LocaleId = #localeId)
IF #customerType = 2
SET #result = 1
ELSE
SET #result = 0
RETURN #result
END
-- Fetch advert details
CREATE PROCEDURE [dbo].[FetchAdvertDetails]
(
#advertId bigint,
#localeId int,
#advert varchar(500) OUTPUT,
#advertUrl varchar(500) OUTPUT,
#advertWidth int OUTPUT,
#advertHeight int OUTPUT
)
AS
BEGIN
-- SET NOCOUNT ON added to prevent extra result sets from
-- interfering with SELECT statements.
SET NOCOUNT ON;
SELECT #advert = T1.Advert, #advertUrl = T1.TargetUrl, #advertWidth = T1.Width, #advertHeight = T1.Height FROM Advert as T1
INNER JOIN Campaign AS T2 ON T1.CampaignId = T2.Id
WHERE T1.Id = #advertId AND T2.LocaleId = #localeId AND T2.Deleted = 0 AND T2.[Status] <> 1
IF #advert IS NULL
RETURN 0
ELSE
RETURN 1
END
--- CanAddStatToAdvert
CREATE PROCEDURE [dbo].[CanAddStatToAdvert]
#type smallint, --- Type of stat to add
#advertId bigint,
#publisherId bigint,
#ip varchar(15),
#ipIsUnique bit,
#success bit OUTPUT,
#unique bit OUTPUT,
#approved bit OUTPUT,
#publisherEarning money OUTPUT,
#advertiserCost money OUTPUT,
#originalStatus smallint OUTPUT,
#campaignId bigint OUTPUT
AS
BEGIN
SET NOCOUNT ON;
DECLARE #campaignLimit int
DECLARE #campaignStatus smallint
DECLARE #advertsLeft int
DECLARE #campaignType smallint
DECLARE #campaignModeration smallint
DECLARE #count int
SELECT #originalStatus = 0
SELECT #success = 1
SELECT #approved = 1
SELECT #unique = 1
SELECT #campaignId = CampaignId FROM dbo.Advert
WHERE Id = #advertId
IF #campaignId IS NULL
BEGIN
SELECT #success = 0
RETURN
END
SELECT #campaignLimit = Limit, #campaignStatus = [Status], #campaignType = [Type], #publisherEarning = PublisherEarning, #advertiserCost = AdvertiserCost, #campaignModeration = ModerationType FROM dbo.Campaign
WHERE Id = #campaignId
IF (#type <> 0 AND #type <> 2 AND #type <> #campaignType) OR ((#campaignType = 0 OR #campaignType = 2) AND (#type = 1)) -- if not a click or view type, then type must match the campaign (ie, only able to do leads on lead campaigns, no isales or etc), click and view campaigns however can do leads too
BEGIN
SELECT #success = 0
RETURN
END
-- Take advantage of the fact that the variable only gets touched if there is a record,
-- which is supposed to override the existing one, if there is one
SELECT #publisherEarning = Earning FROM dbo.MapCampaignPublisherEarning
WHERE CanpaignId = #campaignId AND PublisherId = #publisherId
IF #campaignStatus = 1
BEGIN
SELECT #success = 0
RETURN
END
IF NOT #campaignLimit IS NULL
BEGIN
SELECT #advertsLeft = AdvertsLeft FROM dbo.Campaign WHERE Id = #campaignId
IF #advertsLeft < 1
BEGIN
SELECT #success = 0
RETURN
END
END
IF #campaignModeration = 0 -- blacklist
BEGIN
SELECT #count = COUNT([Status]) FROM dbo.MapCampaignModeration WHERE CampaignId = #campaignId AND PublisherId = #publisherId AND [Status] = 3
IF #count > 0
BEGIN
SELECT #success = 0
RETURN
END
END
ELSE -- whitelist
BEGIN
SELECT #count = COUNT([Status]) FROM dbo.MapCampaignModeration WHERE CampaignId = #campaignId AND PublisherId = #publisherId AND [Status] = 2
IF #count < 1
BEGIN
SELECT #success = 0
RETURN
END
END
IF #ipIsUnique = 1
BEGIN
SELECT #unique = 1
END
ELSE
BEGIN
IF (SELECT COUNT(T1.Id) FROM dbo.Stat AS T1
INNER JOIN dbo.IQ_Advert AS T2
ON T1.AdvertId = T2.Id
WHERE T2.CampaignId = #campaignId
AND T1.[Type] = #type
AND T1.[Unique] = 1
AND T1.PublisherCustomerId = #publisherId
AND T1.Ip = #ip
AND DATEADD(SECOND, 86400, T1.[Date]) > GETDATE()
) = 0
SELECT #unique = 1
ELSE
BEGIN
SELECT #unique = 0, #originalStatus = 1 -- not unique, and set status to be ip conflict
END
END
IF #unique = 0 AND #type <> 0 AND #type <> 2
BEGIN
SELECT #unique = 1, #approved = 0
END
IF #originalStatus = 0
SELECT #originalStatus = 5
IF #approved = 0 OR #type <> #campaignType
BEGIN
SELECT #publisherEarning = 0, #advertiserCost = 0
END
END
I am thinking this needs more than just a couple of indexes thrown in to help it, but rather a total rethinking of how to handle it. I have been heard that running this as a batch would help, but I am not sure how to get this implemented, and really not sure if i can implement it in a such way where I keep all these nice checks before the actual insert or if I have to give up on some of this.
Anyhow, all help would be appreciated, if you need any of the table layouts, let me know :).
Thanks for taking the time to look at it :)

Answer 1

Make sure to reference tables with the ownership prefix. So instead of:
INNER JOIN Campaign AS T2 ON T1.CampaignId = T2.Id
Use
INNER JOIN dbo.Campaign AS T2 ON T1.CampaignId = T2.Id
That will allow the database to cache the execution plan.
Another possibility is to disable database locking, which has data integrity risks, but can significantly increase performance:
INNER JOIN dbo.Campaign AS T2 (nolock) ON T1.CampaignId = T2.Id
Run a sample query in SQL Analyzer with "Show Execution Plan" turned on. This might give you a hint as to the slowest part of the query.

Answer 2

it seems like FetchAdvertDetails hit the same tables as the start of CanAddStatToAdvert (Advert and Campaign). If possible, I'd try to eliminate FetchAdvertDetails and roll its logic into CanAddStatToAdvert, so you don't have the hit Advert and Campaign the extra times.

Answer 3

Get rid of most of the SQL.
This stored procedure does several
checks, it tests up against our
customer database to see if the person
showing the advert (given by a primary
key id) is an actual customer under
the given locale (our system is
running on several languages which are
all run as separate sites). Next up is
all the advert details fetched out
(image location as an url, height and
width of the advert) - and lest step
calls a separate stored procedure to
test if the advert is allowed to be
shown (is the campaign expired by
either date or number of adverts
allowed to show?) and if the customer
has access to it (we got 2 access
systems running, a blacklist and a
whitelist one) and lastly what type of
campaign we're running, is the view
unique and so forth.
Most of this should not be done in the database for every request. In particular:
Customer and local can be stored in memory. Expire them after 5 minutes or so, but do not ask for this info on every repetitive request.
Advert details can also be stored. Every advert will have a "key" to identify it (Number)?. Ust a dictionary / hashtable in memory.
Eliminate as many SQL Parts as you can. Dumping repetitive work on the SQL Database is a typical mistake.