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 Database Table Slow

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pashatest
Starting Member

3 Posts

Posted - 2013-06-12 : 10:11:36
I have two tables in the database: tb_CampaignLead and tb_Feed. Both tables have thousands of rows and have one index each on the primary key. tb_CampaignLead has 20% more data than tb_Feed. Still tb_Feed is 6 times slower than tb_CampaignLead for a SELECT *. Can anyone please tell me why is tb_Feed so slow. The tables structures are below

CREATE TABLE [dbo].[tb_Feed](
[FeedID] [uniqueidentifier] NOT NULL,
[DateCreated] [smalldatetime] NULL,
[LeadSourceID] [int] NULL,
[RawLeadURL] [nvarchar](max) NULL,
[CostPerEnquiry] [money] NULL,
[ResultText] [nvarchar](max) NULL,
[SrcResultText] [nvarchar](max) NULL,
[SrcResult] [bit] NULL,
[Encrypted] [bit] NULL,
[ProductID] [int] NULL,
CONSTRAINT [PK_tb_Feed] PRIMARY KEY CLUSTERED


CREATE TABLE [dbo].[tb_CampaignLead](
[LeadID] [uniqueidentifier] NOT NULL,
[FeedID] [uniqueidentifier] NOT NULL,
[CampaignID] [int] NOT NULL,
[ProductID] [int] NOT NULL,
[CompanyID] [int] NOT NULL,
[LeadSourceID] [int] NOT NULL,
[DateCreated] [smalldatetime] NULL,
[LeadTextEmail] [nvarchar](max) NULL,
[LeadTextOther] [nvarchar](max) NULL,
[DateSent] [smalldatetime] NULL,
[EmailResponse] [nvarchar](max) NULL,
[OtherResponse] [nvarchar](max) NULL,
[EmailOK] [bit] NULL,
[OtherOK] [bit] NULL,
[ResultPass] [bit] NULL,
[L_Title] [nvarchar](50) NULL,
[L_Email] [nvarchar](100) NULL,
[L_Firstname] [nvarchar](max) NULL,
[L_Surname] [nvarchar](max) NULL,
[L_Address1] [nvarchar](max) NULL,
[L_Address2] [nvarchar](max) NULL,
[L_Address3] [nvarchar](max) NULL,
[L_TownCity] [nvarchar](max) NULL,
[L_AreaRegion] [nvarchar](max) NULL,
[L_Country] [nvarchar](max) NULL,
[L_PostCode] [nvarchar](50) NULL,
[L_Telephone1] [nvarchar](50) NULL,
[L_Telephone2] [nvarchar](50) NULL,
[L_DOB] [smalldatetime] NULL,
[L_Extra1] [nvarchar](max) NULL,
[L_Extra2] [nvarchar](max) NULL,
[L_Extra3] [nvarchar](max) NULL,
[L_Extra4] [nvarchar](max) NULL,
[L_Extra5] [nvarchar](max) NULL,
[L_Extra6] [nvarchar](max) NULL,
[L_Extra7] [nvarchar](max) NULL,
[L_Extra8] [nvarchar](max) NULL,
[L_Extra9] [nvarchar](max) NULL,
[L_Extra10] [nvarchar](max) NULL,
[L_Extra11] [nvarchar](max) NULL,
[L_Extra12] [nvarchar](max) NULL,
[L_Extra13] [nvarchar](max) NULL,
[L_Extra14] [nvarchar](max) NULL,
[L_Extra15] [nvarchar](max) NULL,
[L_Extra16] [nvarchar](max) NULL,
[L_Extra17] [nvarchar](max) NULL,
[L_Extra18] [nvarchar](max) NULL,
[L_Extra19] [nvarchar](max) NULL,
[L_Extra20] [nvarchar](max) NULL,
[SourceCost] [money] NULL,
[CampaignCost] [money] NULL,
[DeliveredPass] [bit] NULL,
[FieldReqBWAND] [int] NULL,
[FieldSuppliedBWAND] [int] NULL,
[FilterBWAND] [int] NULL,
[FilterPassBWAND] [int] NULL,
[OPFilterBWAND] [int] NULL,
[OPFilterPassBWAND] [int] NULL,
[ProcessBWAND] [int] NULL,
[ProcessPassBWAND] [int] NULL,
[L_MobileNetwork] [nvarchar](max) NULL,
[SrcResultPass] [bit] NULL,
CONSTRAINT [PK_tb_CampaignLead] PRIMARY KEY CLUSTERED

visakh16
Very Important crosS Applying yaK Herder

52326 Posts

Posted - 2013-06-12 : 10:19:04
is it just a SELECT * or do you've some filter conditions as well using WHERE?

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pashatest
Starting Member

3 Posts

Posted - 2013-06-12 : 10:49:01
Just a SELECT * with no where conditions. Basically for any transaction for tb_feed seems to be much slower than tb_campaignlead.
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visakh16
Very Important crosS Applying yaK Herder

52326 Posts

Posted - 2013-06-12 : 11:43:35
what doesn execution plan sugest?

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pashatest
Starting Member

3 Posts

Posted - 2013-06-12 : 15:42:22
It just says a select of the clustered index scan (the primarykey)
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visakh16
Very Important crosS Applying yaK Herder

52326 Posts

Posted - 2013-06-13 : 00:49:01
is there any other steps that have high cost?

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LoztInSpace
Aged Yak Warrior

940 Posts

Posted - 2013-06-14 : 00:10:49
This is just a guess but I'd say it's likely to be the amount of data you are returning rather than the number of rows.

RawLeadURL] [nvarchar](max) NULL,
[ResultText] [nvarchar](max) NULL,
[SrcResultText] [nvarchar](max) NULL,

These guys can store a ton of data, all of which has to be scooped up and sent across the network. Furthermore, depending on how big they are, they could be stored off-table necessitating more IO when they are retrieved.
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MIK_2008
Master Smack Fu Yak Hacker

1054 Posts

Posted - 2013-06-20 : 14:29:05
"only select without a where condition", scan would be always going to perform by the SQL server.

Perhaps you might want to check the fregmentation and defregment it if required?

Cheers
MIK
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