Table Size meets Missing FK Indexes

I am bringing an oldie back with another twist. I recently ran into the need to correlate information between a couple of different queries that I like to use. The two scripts returned different pieces of data about tables in a database. This information was table size and missing foreign key indexes.

I needed to combine the two queries due to a desire to create indexes on foreign keys based on table size. The premise behind this was to get the biggest bang for the buck initially as we work toward optimizing a database. We happened to know heading into this that some of the larger tables are the most heavily queried tables as well.

So, here is what I did to get that information quickly.

[codesyntax lang=”tsql”]

/* Part I */
--Drop Table #indstats
IF exists (SELECT * FROM tempdb.sys.objects WHERE name like '%#indstats%')
BEGIN
	DROP TABLE tempdb.dbo.#indstats
END

BEGIN
CREATE TABLE #indstats (
         IndStatsID INT PRIMARY KEY CLUSTERED
        ,database_id BIGINT
        ,index_id BIGINT
        ,IndexSizeMB DECIMAL(16,1)
        ,OBJECT_ID	BIGINT
);
END

INSERT INTO #indstats (IndStatsID,database_id,index_id,OBJECT_ID,IndexSizeMB)
        SELECT Row_Number() OVER (ORDER BY OBJECT_ID) AS IndStatsID
				,database_id,index_id,OBJECT_ID
				,CONVERT(DECIMAL(19,2),(SUM(ps.page_count))) * 8 /1024 AS IndexSizeMB
			FROM sys.dm_db_index_physical_stats(DB_ID(),null,NULL,NULL,'SAMPLED') ps
			GROUP BY database_id,OBJECT_ID,index_id;

/* Part II */
DECLARE @dbsize DECIMAL(19,2)

SET NOCOUNT ON

/*
**  Summary data.
*/
BEGIN
	SELECT @dbsize = SUM(CONVERT(DECIMAL(19,2),CASE WHEN type = 0 THEN SIZE ELSE 0 END)) * 8/1024
		FROM sys.database_files

END

/* Part III */
BEGIN
	WITH RegData AS (
		SELECT a.container_id,p.OBJECT_ID,p.index_id,us.database_id
			,FileGroupName = FILEGROUP_NAME(a.data_space_id)
			,TableName = OBJECT_NAME(p.OBJECT_ID)
			,NumRows = p.ROWS
			,UsedPages = IsNull(a.used_pages,0)
			,TotalPages = IsNull(a.total_pages,0)
			,DataSizeMB = CONVERT(DECIMAL(19,2),IsNull(a.used_pages,0)) * 8/1024
			,IndexSizeMB = CASE WHEN ps.index_id &lt; 2 THEN 0 ELSE ps.IndexSizeMB END
			,UserRequests = IsNull(us.user_seeks,0) + IsNull(us.user_scans,0) + IsNull(us.user_lookups,0)
			,UserUpdates = IsNull(us.user_updates,0)
			,LastUpdate = IsNull(us.last_user_update,null)
			,RatioRequestsToUpdates = CAST(IsNull(us.user_seeks,0)
					+ IsNull(us.user_scans,0) + IsNull(us.user_lookups,0) AS REAL)
				/ CAST(CASE us.user_updates WHEN 0 THEN 1 ELSE us.user_updates END AS REAL)
		FROM sys.allocation_units a
			INNER Join sys.partitions p
				ON p.hobt_id = a.container_id
				And a.type = 1
			LEFT Outer Join sys.dm_db_index_usage_stats us
				ON us.OBJECT_ID = p.OBJECT_ID
				And us.index_id = p.index_id
				And us.database_id = DB_ID()
			LEFT Outer Join #indstats ps
				ON p.index_id = ps.index_id
				And ps.database_id = DB_ID()
				And p.OBJECT_ID = ps.OBJECT_ID
		--WHERE OBJECTPROPERTY(p.object_id,'IsMSShipped') = 0
	)
	, LOBData AS (
		SELECT a.container_id,p.OBJECT_ID,p.index_id,us.database_id
			,FileGroupName = FILEGROUP_NAME(a.data_space_id)
			,TableName = OBJECT_NAME(p.OBJECT_ID)
			,NumRows = p.ROWS
			,UsedPages = IsNull(a.used_pages,0)
			,TotalPages = IsNull(a.total_pages,0)
			,DataSizeMB = CONVERT(DECIMAL(19,2),IsNull(a.used_pages,0)) * 8/1024
			,IndexSizeMB = CASE WHEN ps.index_id &lt; 2 THEN 0 ELSE ps.IndexSizeMB END
			,UserRequests = IsNull(us.user_seeks,0) + IsNull(us.user_scans,0) + IsNull(us.user_lookups,0)
			,UserUpdates = IsNull(us.user_updates,0)
			,LastUpdate = IsNull(us.last_user_update,null)
			,RatioRequestsToUpdates = CAST(IsNull(us.user_seeks,0)
					+ IsNull(us.user_scans,0) + IsNull(us.user_lookups,0) AS REAL)
				/ CAST(CASE us.user_updates WHEN 0 THEN 1 ELSE us.user_updates END AS REAL)
		FROM sys.allocation_units a
			INNER Join sys.partitions p
				ON p.partition_id = a.container_id
				And a.type = 2
			LEFT Outer Join sys.dm_db_index_usage_stats us
				ON us.OBJECT_ID = p.OBJECT_ID
				And us.index_id = p.index_id
				And us.database_id = DB_ID()
			LEFT Outer Join #indstats ps
				ON p.index_id = ps.index_id
				And ps.database_id = DB_ID()
				And p.OBJECT_ID = ps.OBJECT_ID
		--WHERE OBJECTPROPERTY(p.object_id,'IsMSShipped') = 0
	)
	, OverFlowData AS (
		SELECT a.container_id,p.OBJECT_ID,p.index_id,us.database_id
			,FileGroupName = FILEGROUP_NAME(a.data_space_id)
			,TableName = OBJECT_NAME(p.OBJECT_ID)
			,NumRows = p.ROWS
			,UsedPages = IsNull(a.used_pages,0)
			,TotalPages = IsNull(a.total_pages,0)
			,DataSizeMB = CONVERT(DECIMAL(19,2),IsNull(a.used_pages,0)) * 8/1024
			,IndexSizeMB = CASE WHEN ps.index_id &lt; 2 THEN 0 ELSE ps.IndexSizeMB END
			,UserRequests = IsNull(us.user_seeks,0) + IsNull(us.user_scans,0) + IsNull(us.user_lookups,0)
			,UserUpdates = IsNull(us.user_updates,0)
			,LastUpdate = IsNull(us.last_user_update,null)
			,RatioRequestsToUpdates = CAST(IsNull(us.user_seeks,0)
					+ IsNull(us.user_scans,0) + IsNull(us.user_lookups,0) AS REAL)
				/ CAST(CASE us.user_updates WHEN 0 THEN 1 ELSE us.user_updates END AS REAL)
		FROM sys.allocation_units a
			INNER Join sys.partitions p
				ON p.hobt_id = a.container_id
				And a.type = 3
			LEFT Outer Join sys.dm_db_index_usage_stats us
				ON us.OBJECT_ID = p.OBJECT_ID
				And us.index_id = p.index_id
				And us.database_id = DB_ID()
			LEFT Outer Join #indstats ps
				ON p.index_id = ps.index_id
				And ps.database_id = DB_ID()
				And p.OBJECT_ID = ps.OBJECT_ID
		--WHERE OBJECTPROPERTY(p.object_id,'IsMSShipped') = 0
	), IndexSum AS (
		SELECT a.OBJECT_ID
		,AllDataSizeMB = SUM(CASE WHEN a.index_id in (0,1)
							THEN IsNull(a.DataSizeMB,0) +  IsNull(p2.DataSizeMB,0) +  IsNull(p3.DataSizeMB,0)
							ELSE IsNull(p2.DataSizeMB,0) + IsNull(p3.DataSizeMB,0)
							END)
		FROM RegData a
			LEFT Outer Join LOBData p2
				ON p2.container_id = a.container_id
			LEFT Outer Join OverFlowData p3
				ON p3.container_id = a.container_id
		GROUP BY a.OBJECT_ID
	), SummaryInfo AS (
		SELECT
			TableName = MAX(a.TableName)
			,InRowDataSizeMB = SUM(IsNull(a.DataSizeMB,0))
			,LOBDataSizeMB = SUM(IsNull(p2.DataSizeMB,0))
			,OFlowDataSizeMB = SUM(IsNull(p3.DataSizeMB,0))
			,NumRows = MAX(COALESCE(a.NumRows,p2.NumRows,p3.NumRows,0))
			,AllUsedPages = SUM(IsNull(a.UsedPages,0) + IsNull(p2.UsedPages,0) + IsNull(p3.UsedPages,0))
			,AllPages = SUM(IsNull(a.TotalPages,0) + IsNull(p2.TotalPages,0) + IsNull(p3.TotalPages,0))
			,FreeDataSpace = CONVERT(DECIMAL(19,2),
				SUM(IsNull(a.TotalPages,0) + IsNull(p2.TotalPages,0) + IsNull(p3.TotalPages,0))
				- SUM(IsNull(a.UsedPages,0) + IsNull(p2.UsedPages,0) + IsNull(p3.UsedPages,0)))* 8 / 1024
			,AllDataSizeMB = MAX(ids.AllDataSizeMB)
			,IndexSizeMB = SUM(IsNull(a.IndexSizeMB,0))
				+ SUM(IsNull(p2.IndexSizeMB,0)) + SUM(IsNull(p3.IndexSizeMB,0))
			,UserRequests = AVG(IsNull(a.UserRequests,0)
				+ IsNull(p2.UserRequests,0) + IsNull(p3.UserRequests,0))
			,UserUpdates = AVG(IsNull(a.UserUpdates,0) + IsNull(p2.UserUpdates,0) + IsNull(p3.UserUpdates,0))
			,LastUpdate = MAX(COALESCE(a.LastUpdate,p2.LastUpdate,p3.LastUpdate,null))
			,DatabaseSize = @dbsize
		FROM RegData a
			LEFT Outer Join LOBData p2
				ON p2.container_id = a.container_id
			LEFT Outer Join OverFlowData p3
				ON p3.container_id = a.container_id
			LEFT Outer Join sys.indexes i
				ON i.OBJECT_ID = a.OBJECT_ID
				And i.index_id = a.index_id
			LEFT Outer Join IndexSum ids
				ON i.OBJECT_ID = ids.OBJECT_ID
		GROUP BY a.OBJECT_ID
	), TotalUnused AS (
				SELECT SUM(FreeDataSpace) AS UnusedSpace
					FROM SummaryInfo
		)
	SELECT TableName,ChildTableColumn as MissingFKIndexColumn,NumRows,InRowDataSizeMB,LOBDataSizeMB,OFlowDataSizeMB
			,AllUsedPages,AllPages
			,FreeDataSpace,AllDataSizeMB,IndexSizeMB
			,TableSizeMB = AllDataSizeMB + IndexSizeMB + FreeDataSpace
			,UserRequests,UserUpdates,LastUpdate
			,PercentofDB = ((IndexSizeMB + AllDataSizeMB) / DatabaseSize) * 100
			,DatabaseSize
			,DataUsedSize = DatabaseSize - TU.UnusedSpace
			,PercentofDataFileUsed = ((IndexSizeMB + AllDataSizeMB) / (DatabaseSize - TU.UnusedSpace)) * 100
		FROM SummaryInfo SI
			CROSS APPLY TotalUnused TU
			Cross Apply (SELECT
								OBJECT_NAME(FK.parent_object_id) AS FKtable
								,OBJECT_NAME(Fk.referenced_object_id) AS ReferencesThisTable
								,OBJECT_NAME(FK.constraint_object_id) AS FKName
								,C.name ChildTableColumn
							FROM sys.foreign_key_columns FK
								INNER JOIN sys.columns C
									ON FK.parent_object_id = C.object_id 
									AND FK.parent_column_id = C.column_id
								INNER JOIN sys.objects O
									On FK.parent_object_id = o.object_id
								LEFT OUTER JOIN sys.index_columns ic
									ON FK.parent_object_id = ic.object_id
									AND FK.parent_column_id = ic.column_id 
							WHERE ic.object_id IS NULL) FK
		Where Fk.fktable = SI.TableName
		ORDER BY PercentofDB DESC
END

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/* Part I */

--Drop Table #indstats

IF exists (SELECT * FROM tempdb.sys.objects WHERE name like '%#indstats%')

BEGIN

DROP TABLE tempdb.dbo.#indstats

END

BEGIN

CREATE TABLE #indstats (

IndStatsID INT PRIMARY KEY CLUSTERED

,database_id BIGINT

,index_id BIGINT

,IndexSizeMB DECIMAL(16,1)

,OBJECT_ID BIGINT

);

END

INSERT INTO #indstats (IndStatsID,database_id,index_id,OBJECT_ID,IndexSizeMB)

SELECT Row_Number() OVER (ORDER BY OBJECT_ID) AS IndStatsID

,database_id,index_id,OBJECT_ID

,CONVERT(DECIMAL(19,2),(SUM(ps.page_count))) * 8 /1024 AS IndexSizeMB

FROM sys.dm_db_index_physical_stats(DB_ID(),null,NULL,NULL,'SAMPLED') ps

GROUP BY database_id,OBJECT_ID,index_id;

/* Part II */

DECLARE @dbsize DECIMAL(19,2)

SET NOCOUNT ON

** Summary data.

BEGIN

SELECT @dbsize = SUM(CONVERT(DECIMAL(19,2),CASE WHEN type = 0 THEN SIZE ELSE 0 END)) * 8/1024

FROM sys.database_files

END

/* Part III */

BEGIN

WITH RegData AS (

SELECT a.container_id,p.OBJECT_ID,p.index_id,us.database_id

,FileGroupName = FILEGROUP_NAME(a.data_space_id)

,TableName = OBJECT_NAME(p.OBJECT_ID)

,NumRows = p.ROWS

,UsedPages = IsNull(a.used_pages,0)

,TotalPages = IsNull(a.total_pages,0)

,DataSizeMB = CONVERT(DECIMAL(19,2),IsNull(a.used_pages,0)) * 8/1024

,IndexSizeMB = CASE WHEN ps.index_id < 2 THEN 0 ELSE ps.IndexSizeMB END

,UserRequests = IsNull(us.user_seeks,0) + IsNull(us.user_scans,0) + IsNull(us.user_lookups,0)

,UserUpdates = IsNull(us.user_updates,0)

,LastUpdate = IsNull(us.last_user_update,null)

,RatioRequestsToUpdates = CAST(IsNull(us.user_seeks,0)

+ IsNull(us.user_scans,0) + IsNull(us.user_lookups,0) AS REAL)

/ CAST(CASE us.user_updates WHEN 0 THEN 1 ELSE us.user_updates END AS REAL)

FROM sys.allocation_units a

INNER Join sys.partitions p

ON p.hobt_id = a.container_id

And a.type = 1

LEFT Outer Join sys.dm_db_index_usage_stats us

ON us.OBJECT_ID = p.OBJECT_ID

And us.index_id = p.index_id

And us.database_id = DB_ID()

LEFT Outer Join #indstats ps

ON p.index_id = ps.index_id

And ps.database_id = DB_ID()

And p.OBJECT_ID = ps.OBJECT_ID

--WHERE OBJECTPROPERTY(p.object_id,'IsMSShipped') = 0

)

, LOBData AS (

SELECT a.container_id,p.OBJECT_ID,p.index_id,us.database_id

,FileGroupName = FILEGROUP_NAME(a.data_space_id)

,TableName = OBJECT_NAME(p.OBJECT_ID)

,NumRows = p.ROWS

,UsedPages = IsNull(a.used_pages,0)

,TotalPages = IsNull(a.total_pages,0)

,DataSizeMB = CONVERT(DECIMAL(19,2),IsNull(a.used_pages,0)) * 8/1024

,IndexSizeMB = CASE WHEN ps.index_id < 2 THEN 0 ELSE ps.IndexSizeMB END

,UserRequests = IsNull(us.user_seeks,0) + IsNull(us.user_scans,0) + IsNull(us.user_lookups,0)

,UserUpdates = IsNull(us.user_updates,0)

,LastUpdate = IsNull(us.last_user_update,null)

,RatioRequestsToUpdates = CAST(IsNull(us.user_seeks,0)

+ IsNull(us.user_scans,0) + IsNull(us.user_lookups,0) AS REAL)

/ CAST(CASE us.user_updates WHEN 0 THEN 1 ELSE us.user_updates END AS REAL)

FROM sys.allocation_units a

INNER Join sys.partitions p

ON p.partition_id = a.container_id

And a.type = 2

LEFT Outer Join sys.dm_db_index_usage_stats us

ON us.OBJECT_ID = p.OBJECT_ID

And us.index_id = p.index_id

And us.database_id = DB_ID()

LEFT Outer Join #indstats ps

ON p.index_id = ps.index_id

And ps.database_id = DB_ID()

And p.OBJECT_ID = ps.OBJECT_ID

--WHERE OBJECTPROPERTY(p.object_id,'IsMSShipped') = 0

)

, OverFlowData AS (

SELECT a.container_id,p.OBJECT_ID,p.index_id,us.database_id

,FileGroupName = FILEGROUP_NAME(a.data_space_id)

,TableName = OBJECT_NAME(p.OBJECT_ID)

,NumRows = p.ROWS

,UsedPages = IsNull(a.used_pages,0)

,TotalPages = IsNull(a.total_pages,0)

,DataSizeMB = CONVERT(DECIMAL(19,2),IsNull(a.used_pages,0)) * 8/1024

,IndexSizeMB = CASE WHEN ps.index_id < 2 THEN 0 ELSE ps.IndexSizeMB END

,UserRequests = IsNull(us.user_seeks,0) + IsNull(us.user_scans,0) + IsNull(us.user_lookups,0)

,UserUpdates = IsNull(us.user_updates,0)

,LastUpdate = IsNull(us.last_user_update,null)

,RatioRequestsToUpdates = CAST(IsNull(us.user_seeks,0)

+ IsNull(us.user_scans,0) + IsNull(us.user_lookups,0) AS REAL)

/ CAST(CASE us.user_updates WHEN 0 THEN 1 ELSE us.user_updates END AS REAL)

FROM sys.allocation_units a

INNER Join sys.partitions p

ON p.hobt_id = a.container_id

And a.type = 3

LEFT Outer Join sys.dm_db_index_usage_stats us

ON us.OBJECT_ID = p.OBJECT_ID

And us.index_id = p.index_id

And us.database_id = DB_ID()

LEFT Outer Join #indstats ps

ON p.index_id = ps.index_id

And ps.database_id = DB_ID()

And p.OBJECT_ID = ps.OBJECT_ID

--WHERE OBJECTPROPERTY(p.object_id,'IsMSShipped') = 0

), IndexSum AS (

SELECT a.OBJECT_ID

,AllDataSizeMB = SUM(CASE WHEN a.index_id in (0,1)

THEN IsNull(a.DataSizeMB,0) + IsNull(p2.DataSizeMB,0) + IsNull(p3.DataSizeMB,0)

ELSE IsNull(p2.DataSizeMB,0) + IsNull(p3.DataSizeMB,0)

END)

FROM RegData a

LEFT Outer Join LOBData p2

ON p2.container_id = a.container_id

LEFT Outer Join OverFlowData p3

ON p3.container_id = a.container_id

GROUP BY a.OBJECT_ID

), SummaryInfo AS (

SELECT

TableName = MAX(a.TableName)

,InRowDataSizeMB = SUM(IsNull(a.DataSizeMB,0))

,LOBDataSizeMB = SUM(IsNull(p2.DataSizeMB,0))

,OFlowDataSizeMB = SUM(IsNull(p3.DataSizeMB,0))

,NumRows = MAX(COALESCE(a.NumRows,p2.NumRows,p3.NumRows,0))

,AllUsedPages = SUM(IsNull(a.UsedPages,0) + IsNull(p2.UsedPages,0) + IsNull(p3.UsedPages,0))

,AllPages = SUM(IsNull(a.TotalPages,0) + IsNull(p2.TotalPages,0) + IsNull(p3.TotalPages,0))

,FreeDataSpace = CONVERT(DECIMAL(19,2),

SUM(IsNull(a.TotalPages,0) + IsNull(p2.TotalPages,0) + IsNull(p3.TotalPages,0))

- SUM(IsNull(a.UsedPages,0) + IsNull(p2.UsedPages,0) + IsNull(p3.UsedPages,0)))* 8 / 1024

,AllDataSizeMB = MAX(ids.AllDataSizeMB)

,IndexSizeMB = SUM(IsNull(a.IndexSizeMB,0))

+ SUM(IsNull(p2.IndexSizeMB,0)) + SUM(IsNull(p3.IndexSizeMB,0))

,UserRequests = AVG(IsNull(a.UserRequests,0)

+ IsNull(p2.UserRequests,0) + IsNull(p3.UserRequests,0))

,UserUpdates = AVG(IsNull(a.UserUpdates,0) + IsNull(p2.UserUpdates,0) + IsNull(p3.UserUpdates,0))

,LastUpdate = MAX(COALESCE(a.LastUpdate,p2.LastUpdate,p3.LastUpdate,null))

,DatabaseSize = @dbsize

FROM RegData a

LEFT Outer Join LOBData p2

ON p2.container_id = a.container_id

LEFT Outer Join OverFlowData p3

ON p3.container_id = a.container_id

LEFT Outer Join sys.indexes i

ON i.OBJECT_ID = a.OBJECT_ID

And i.index_id = a.index_id

LEFT Outer Join IndexSum ids

ON i.OBJECT_ID = ids.OBJECT_ID

GROUP BY a.OBJECT_ID

), TotalUnused AS (

SELECT SUM(FreeDataSpace) AS UnusedSpace

FROM SummaryInfo

)

SELECT TableName,ChildTableColumn as MissingFKIndexColumn,NumRows,InRowDataSizeMB,LOBDataSizeMB,OFlowDataSizeMB

,AllUsedPages,AllPages

,FreeDataSpace,AllDataSizeMB,IndexSizeMB

,TableSizeMB = AllDataSizeMB + IndexSizeMB + FreeDataSpace

,UserRequests,UserUpdates,LastUpdate

,PercentofDB = ((IndexSizeMB + AllDataSizeMB) / DatabaseSize) * 100

,DatabaseSize

,DataUsedSize = DatabaseSize - TU.UnusedSpace

,PercentofDataFileUsed = ((IndexSizeMB + AllDataSizeMB) / (DatabaseSize - TU.UnusedSpace)) * 100

FROM SummaryInfo SI

CROSS APPLY TotalUnused TU

Cross Apply (SELECT

OBJECT_NAME(FK.parent_object_id) AS FKtable

,OBJECT_NAME(Fk.referenced_object_id) AS ReferencesThisTable

,OBJECT_NAME(FK.constraint_object_id) AS FKName

,C.name ChildTableColumn

FROM sys.foreign_key_columns FK

INNER JOIN sys.columns C

ON FK.parent_object_id = C.object_id

AND FK.parent_column_id = C.column_id

INNER JOIN sys.objects O

On FK.parent_object_id = o.object_id

LEFT OUTER JOIN sys.index_columns ic

ON FK.parent_object_id = ic.object_id

AND FK.parent_column_id = ic.column_id

WHERE ic.object_id IS NULL) FK

Where Fk.fktable = SI.TableName

ORDER BY PercentofDB DESC

END

[/codesyntax]

The change is not overly much. I added a subquery via a cross apply to get the missing foreign key info. Then I return the pertinent columns back to the Select query.

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