If a table has two xml columns, will inserting records be a lot slower?
- by Lieven Cardoen
Is it a bad thing to have two xml columns in one table? + How much slower are these xml columns in terms of updating/inserting/reading data?
In profiler this kind of insert normally takes 0 ms, but sometimes it goes up to 160ms:
declare @p8 xml
set @p8=convert(xml,N'<interactions><interaction correct="false" score="0"
id="0" gapid="0" x="61" y="225"><feedback/><element id="0" position="0"
elementtype="1"><asset/></element></interaction><interaction correct="false"
score="0" id="1" gapid="1" x="64" y="250"><feedback/><element id="0" position="0"
elementtype="1"><asset/></element></interaction><interaction correct="false"
score="0" id="2" gapid="2" x="131" y="250"><feedback/><element id="0" position="0"
elementtype="1"><asset/></element></interaction></interactions>')
declare @p14 xml
set @p14=convert(xml,N'<contentinteractions/>')
exec sp_executesql N'INSERT INTO
[dbo].[PackageSessionNodes]([dbo].[PackageSessionNodes].[PackageSessionId],
[dbo].[PackageSessionNodes].[TreeNodeId],[dbo].[PackageSessionNodes].[Duration],
[dbo].[PackageSessionNodes].[Score],[dbo].[PackageSessionNodes].[ScoreMax],
[dbo].[PackageSessionNodes].[Interactions],[dbo].[PackageSessionNodes].[BrainTeaser],
[dbo].[PackageSessionNodes].[DateCreated],
[dbo].[PackageSessionNodes].[CompletionStatus],
[dbo].[PackageSessionNodes].[ReducedScore],
[dbo].[PackageSessionNodes].[ReducedScoreMax],
[dbo].[PackageSessionNodes].[ContentInteractions])
VALUES (@ins_dboPackageSessionNodesPackageSessionId,
@ins_dboPackageSessionNodesTreeNodeId,
@ins_dboPackageSessionNodesDuration,
@ins_dboPackageSessionNodesScore,
@ins_dboPackageSessionNodesScoreMax,
@ins_dboPackageSessionNodesInteractions,
@ins_dboPackageSessionNodesBrainTeaser,
@ins_dboPackageSessionNodesDateCreated,
@ins_dboPackageSessionNodesCompletionStatus,
@ins_dboPackageSessionNodesReducedScore,
@ins_dboPackageSessionNodesReducedScoreMax,
@ins_dboPackageSessionNodesContentInteractions)
;
SELECT SCOPE_IDENTITY() as new_id
This is the table:
CREATE TABLE [dbo].[PackageSessionNodes](
[PackageSessionNodeId] [int] IDENTITY(1,1) NOT NULL,
[PackageSessionId] [int] NOT NULL,
[TreeNodeId] [int] NOT NULL,
[Duration] [int] NULL,
[Score] [float] NOT NULL,
[ScoreMax] [float] NOT NULL,
[Interactions] [xml] NOT NULL,
[BrainTeaser] [bit] NOT NULL,
[DateCreated] [datetime] NULL,
[CompletionStatus] [int] NOT NULL,
[ReducedScore] [float] NOT NULL,
[ReducedScoreMax] [float] NOT NULL,
[ContentInteractions] [xml] NOT NULL,
CONSTRAINT [PK_PackageSessionNodes] PRIMARY KEY CLUSTERED
(
[PackageSessionNodeId] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF,
ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]
GO
ALTER TABLE [dbo].[PackageSessionNodes] WITH CHECK ADD CONSTRAINT
[FK_PackageSessionNodes_PackageSessions] FOREIGN KEY([PackageSessionId])
REFERENCES [dbo].[PackageSessions] ([PackageSessionId])
ON UPDATE CASCADE
ON DELETE CASCADE
GO
ALTER TABLE [dbo].[PackageSessionNodes] CHECK CONSTRAINT
[FK_PackageSessionNodes_PackageSessions]
GO
ALTER TABLE [dbo].[PackageSessionNodes] WITH CHECK ADD CONSTRAINT
[FK_PackageSessionNodes_TreeNodes] FOREIGN KEY([TreeNodeId])
REFERENCES [dbo].[TreeNodes] ([TreeNodeId])
GO
ALTER TABLE [dbo].[PackageSessionNodes] CHECK CONSTRAINT
[FK_PackageSessionNodes_TreeNodes]
GO
ALTER TABLE [dbo].[PackageSessionNodes] ADD CONSTRAINT
[DF_PackageSessionNodes_Score] DEFAULT ((-1)) FOR [Score]
GO
ALTER TABLE [dbo].[PackageSessionNodes] ADD CONSTRAINT
[DF_PackageSessionNodes_ScoreMax] DEFAULT ((-1)) FOR [ScoreMax]
GO
ALTER TABLE [dbo].[PackageSessionNodes] ADD CONSTRAINT
[DF_PackageSessionNodes_DateCreated] DEFAULT (getdate()) FOR [DateCreated]
GO
ALTER TABLE [dbo].[PackageSessionNodes] ADD CONSTRAINT
[DF_PackageSessionNodes_ReducedScore] DEFAULT ((-1)) FOR [ReducedScore]
GO
ALTER TABLE [dbo].[PackageSessionNodes] ADD CONSTRAINT
[DF_PackageSessionNodes_ReducedScoreMax] DEFAULT ((-1)) FOR [ReducedScoreMax]
GO
