I'm using sys.dm_db_missing_index_details to find missing indexes on a database that is currently in testing. After running a bunch of our reports, there are several suggested indexes on 3 or 4 columns that have 15 - 20 included columns. The included columns are mostly varchars ranging from 1 to 150 characters along with a couple of date columns. My index size on that table is already nearly twice the size of the data.
I don't think it's a good idea to add an index with that many columns, but the information I've read on included columns is very general. I'm wondering if there is something about them that I don't understand that would make this a good idea.
As I am creating the non-clustered indexes for the tables, I dont quite understand how dose it really matter to put the columns in the index key columns or put them into the included columns of the index?
I am really confused about that and I am looking forward to hearing from you and thank you very much again for your advices and help.
I am trying to tune a process that is running slowly. I analyzed the process using the Database Engine Tuning Advisor, and it recommended the creation of 3 indexes, all non-clustered:
1) ColA, include ColB 2) ColA, include ColC 3) ColA, include ColD
So... I created a single non-clustered index on:
4) ColA, include ColB, ColC, ColD
That should do the same thing, right? A look at my execution plan shows that the index I created is being scanned -- 3 times. What is puzzling me, though, is that the Database Engine Tuning Advisor is still recommending I create these 3 separate indexes, even with the index (4) that I created in existence.
If it matters, ColA, ColB, ColC and ColD are all int FKs.
I would like to know the impacts (if any) of adding nonclustered index with included columns on large tables (these tables are populated by bulk insert from text files).
How do you index through a set of Columns Programmatically using SQL. I have a Table all the columns have the same data for different dates. Column names are Col_0, Col_1, Col_2,.....Col_100, Col_101. I need to perform the same calculation on each column to manipulate the data into a different table. Is it possible to do a While loop that changes the Column name in a SELECT statement. I have tried to do this but can't seem to get it to work. Please help !
I am trying to index through the columns of MyTable so I can do the same work on all columns. I know how to get the column names from MyTable but when I use @MyColName in the SELECT statement to get MyTable Column 0 Row values I get a table with the column name in each row cell. I can't get the syntax correct to return the value in each cell for that column. This is a extremely simplified example !!!!!!DECLARE @MyColName nvarchar(30) --Get the MyTable Column 0 NameSELECT @MyColName = Col_Name(Object_ID('MyTable'), 0) --Display the MyTable Column 0 Row valuesSELECT @MyColName FROM MyTable --This is the syntax I can not get correct
Is there a dynamic management view or system procedure which I can use to find out what columns are in an index, what columns are as an INCLUDE in the index and whether or not the column(s) are ascending or descending. This is excluding the utilities I already know about below:
sys.indexes sys.index_columns sp_helpindex dm_db_index_physical_stats dm_db_index_operational_stats I only ask because it is a pain to look through the sys.indexes and sys.index_columns tables every time I want to know about what columns are in the index created. I also know that scripting the index would give me the information I need but there must be a better way.
When creating a column store index, are there any reasons not to include all columns, besides index size of course? i.e. will the index be more versatile with more columns or should I treat it exactly like its a standard index, putting only necessary columns, in the correct order?
Table DDL below:The tables I have contain Timesheet information. Each row in thetblTSCollected table contains an entry for an employee into thetimesheet system, specifically by scanning the barcode on their badge.A whole bunch of business logic periodically attempts to "pair" theseinto logically matched scans. For example, some employees will scan inand out of a single place of work. For these there will be a rowwritten to the tblTSRuleApplied table which contains, inter alia andsome redundant data, the fldCollectedID for the two rows. The earlierwill be put into the fldStartTimeCollectedID, and the later into thefldEndTimeCollectedID. Some employees will clock on at their base,then perform sub-duties at different locations during the day, andclock off at their home base at the end of their shift. For these, thesystem would identify the outer records as a matching pair, and thenpair up inner records by location.However, if the employee fails to enter a valid "clocking in and out"pair (for example, if they clock in at the wrong location) the systemneeds to generate a "dummy" "clocking in and out" record for thepayroll department. Ideally, this would have NULL values in thefldStartTimeCollectedID and fldEndTimeCollectedID columns. This wouldalert a user in a different part of the system, where missingtimesheets were being arbitrated, that an employee appeared to havefailed to clock in for that day. Of course, the user could seeon-screen that they had clocked in, but at an incorrect location.Unfortunately, the database designer is not here for the moment (he wasknocked off his bicycle recently), but he put a unique index on thetblTSRuleApplied table that prevents the same value being entered intothe fldStartTimeCollectedID and fldEndTimeCollectedID columns. This isgenerally A Good Thing, since we don't want the same timesheet scan toform both a "clocking on" event and a "clocking off" event.So, is there any way of retaining the requirement that thefldStartTimeCollectedID and the fldEndTimeCollectedID columns may notcontain the same value in a single row, UNLESS that value is NULL inwhich case all is hunky dory. I should add that the clients don't muchcare for Triggers (and neither do I for that matter).Many thanks if you are able to help.Edwardif exists (select * from dbo.sysobjects where id =object_id(N'[dbo].[FK_tblTSRuleApplied_tblTSCollected]') andOBJECTPROPERTY(id, N'IsForeignKey') = 1)ALTER TABLE [dbo].[tblTSRuleApplied] DROP CONSTRAINTFK_tblTSRuleApplied_tblTSCollectedGOif exists (select * from dbo.sysobjects where id =object_id(N'[dbo].[FK_tblTSRuleApplied_tblTSCollected1]') andOBJECTPROPERTY(id, N'IsForeignKey') = 1)ALTER TABLE [dbo].[tblTSRuleApplied] DROP CONSTRAINTFK_tblTSRuleApplied_tblTSCollected1GOif exists (select * from dbo.sysobjects where id =object_id(N'[dbo].[FK_tblTSArbAccept_tblTSRuleApplied]') andOBJECTPROPERTY(id, N'IsForeignKey') = 1)ALTER TABLE [dbo].[tblTSArbAccept] DROP CONSTRAINTFK_tblTSArbAccept_tblTSRuleAppliedGOif exists (select * from dbo.sysobjects where id =object_id(N'[dbo].[FK_tblTSCollected_tblTSRuleApplied]') andOBJECTPROPERTY(id, N'IsForeignKey') = 1)ALTER TABLE [dbo].[tblTSCollected] DROP CONSTRAINTFK_tblTSCollected_tblTSRuleAppliedGOif exists (select * from dbo.sysobjects where id =object_id(N'[dbo].[tblTSCollected]') and OBJECTPROPERTY(id,N'IsUserTable') = 1)drop table [dbo].[tblTSCollected]GOif exists (select * from dbo.sysobjects where id =object_id(N'[dbo].[tblTSRuleApplied]') and OBJECTPROPERTY(id,N'IsUserTable') = 1)drop table [dbo].[tblTSRuleApplied]GOCREATE TABLE [dbo].[tblTSCollected] ([fldCollectedID] [int] IDENTITY (1, 1) NOT NULL ,[fldEmployeeID] [int] NULL ,[fldLocationCode] [varchar] (50) COLLATE SQL_Latin1_General_CP1_CI_ASNULL ,[fldTimeStamp] [datetime] NULL ,[fldRuleAppliedID] [int] NULL ,[fldBarCode] [varchar] (50) COLLATE SQL_Latin1_General_CP1_CI_AS NULL,[fldProcessed] [smallint] NOT NULL) ON [PRIMARY]GOCREATE TABLE [dbo].[tblTSRuleApplied] ([fldEmpRuleID] [int] NOT NULL ,[fldRuleAppliedID] [int] IDENTITY (1, 1) NOT NULL ,[fldStartTime] [datetime] NULL ,[fldEndTime] [datetime] NULL ,[fldStartTimeCollectedID] [int] NULL ,[fldEndTimeCollectedID] [int] NULL ,[fldStartArbStatus] [smallint] NULL ,[fldEndArbStatus] [smallint] NULL ,[fldDurationArbStatus] [smallint] NULL ,[fldPrimary] [smallint] NOT NULL ,[fldDateEntered] [datetime] NULL ,[fldEnteredBy] [int] NULL) ON [PRIMARY]GOALTER TABLE [dbo].[tblTSCollected] WITH NOCHECK ADDCONSTRAINT [DF_tblTSCollected_fldProcessed] DEFAULT (0) FOR[fldProcessed],CONSTRAINT [PK_tblTimesheetCollected] PRIMARY KEY CLUSTERED([fldCollectedID]) WITH FILLFACTOR = 90 ON [PRIMARY]GOALTER TABLE [dbo].[tblTSRuleApplied] WITH NOCHECK ADDCONSTRAINT [DF_tblTSRuleApplied_fldPrimary] DEFAULT (1) FOR[fldPrimary],CONSTRAINT [PK_tblTSRuleApplied] PRIMARY KEY CLUSTERED([fldRuleAppliedID]) WITH FILLFACTOR = 90 ON [PRIMARY] ,CONSTRAINT [IX_tblTSRuleApplied_1] UNIQUE NONCLUSTERED([fldStartTimeCollectedID],[fldEndTimeCollectedID]) WITH FILLFACTOR = 90 ON [PRIMARY]GOALTER TABLE [dbo].[tblTSCollected] ADDCONSTRAINT [FK_tblTSCollected_tblEmployee1] FOREIGN KEY([fldEmployeeID]) REFERENCES [dbo].[tblEmployee] ([fldEmployeeID]),CONSTRAINT [FK_tblTSCollected_tblLocation] FOREIGN KEY([fldLocationCode]) REFERENCES [dbo].[tblLocation] ([fldLocationCode]),CONSTRAINT [FK_tblTSCollected_tblTSRuleApplied] FOREIGN KEY([fldRuleAppliedID]) REFERENCES [dbo].[tblTSRuleApplied] ([fldRuleAppliedID])GOALTER TABLE [dbo].[tblTSRuleApplied] ADDCONSTRAINT [FK_tblTSRuleApplied_tblTSCollected] FOREIGN KEY([fldStartTimeCollectedID]) REFERENCES [dbo].[tblTSCollected] ([fldCollectedID]),CONSTRAINT [FK_tblTSRuleApplied_tblTSCollected1] FOREIGN KEY([fldEndTimeCollectedID]) REFERENCES [dbo].[tblTSCollected] ([fldCollectedID]),CONSTRAINT [FK_tblTSRuleApplied_tblTSDurationStatus] FOREIGN KEY([fldDurationArbStatus]) REFERENCES [dbo].[tblTSDurationStatus] ([fldStatus]),CONSTRAINT [FK_tblTSRuleApplied_tblTSEmpRules] FOREIGN KEY([fldEmpRuleID]) REFERENCES [dbo].[tblTSEmpRules] ([fldEmpRuleID]),CONSTRAINT [FK_tblTSRuleApplied_tblTSTimeStatus] FOREIGN KEY([fldStartArbStatus]) REFERENCES [dbo].[tblTSTimeStatus] ([fldStatus]),CONSTRAINT [FK_tblTSRuleApplied_tblTSTimeStatus1] FOREIGN KEY([fldEndArbStatus]) REFERENCES [dbo].[tblTSTimeStatus] ([fldStatus])GO
Hi,I would like to add a unique index that consists of two fields in atable.e.g. tbl_A (field1,field2) -- field1 & field2 Indexed and combinationmust be Unique.Can anyone tell me the actual sql syntax to create this index?Thanks,June.
I have 2 columns in a table namely ColA and ColB.all DML operations are through views n every view has Where clause i.e where ColA=€?€? with check option . All most all my DML queries are using where clause on ColB Where ColB=€?€?
Now my question is I have a clusted index on both ColA and ColB.in which order I have to create cluster index . i.e ColA ASC,ColB ASC or ColB ASC,ColA ASC.
Is there any performance gain we can achieve with their order
I am upgrading from Access, where you can only have 10 fields in a primary key or unique index. Is this also the limit in SQL Server? If not, what is the limit?
Hello, I will explain myself further. I want to make my table in such a way that no two colums have the same value for example: Row 1 - Column 1 = "cool" Row 1 - Column 3 = 91 Row 3 - Column 1 = "cool" Row 3 - Column 3 = 91
I dont care about one column having duplicate values, I want to protect against Column 1 and 3 having the same values on other rows. Is this possible to do in sql server?
SQL Server 2005 has a new very useful feature for creating non-clustered indexes called INCLUDE <columns> which are very helpful when trying to create covering indexes.
Does anyone know of a way to retrieve these INCLUDE columns through any of the system metadata tables? The sp_helpIndex stored procedure is what I currently use but that only returns the (sorted) index columns and not the include columns.
I have a table with clustered index on that. I have only 5 columns in that table. Execution plan is showing that Index scan occurred. What are the cause of the Index scan how can we change that to index seek?
I am giving that kind of similar query below
SELECT @ProductID= ProductID FROM Product WITH (NOLOCK) WHERE SalesID= '@salesId' and Product = 'Clothes '
I think I need to only create few if an index is covering all columns then I do not need to create more indexes for separate columns or should I create separate index as suggested?
Similarly:
CREATE INDEX [NCIX_20187_20186_TL_SRV_Stationary_Stock_Transact] ON [TL_SRV_Stationary_Stock_Transaction] ([SerialNo],[StationaryStatus]) GO CREATE INDEX [NCIX_20189_20188_TL_SRV_Stationary_Stock_Transact] ON [TL_SRV_Stationary_Stock_Transaction] ([StationaryStatus]) INCLUDE ([SerialNo]) GO
[Code] ....
Should I create all indexes above or use minimum number of indexes which covers all columns as mentioned in above create index statements?
If I delete 5 or more columns from a table I get the error "Index was outside the bounds of the array", OK is the only response. I then have to close the report and then open it again.
Easy fix is don't delete more than 5 columns, but my template is setup with 15 columns as it's far quicker to delete them as it is to add them 1 by 1 each time. I've finally got around to looking for a hotfix or something similar but can find no mention of this exact error relating to table column deleting.
Anyone else experience this or know if there is a hotfix for it?
Usually it is better to include the columns in the index that are in where clause, select list and join.I am thinking that the columns in the selected list is better to keep as index columns and the columns that are in the where clause is better to keep in key columns.Where do we use join column is it better to create as main key column or included column.
We are on SQL 2014...we have a bunch of views in a database where we are trying to find the views which have more than 16 columns max for unique index/constraint...this is needed so we can convert them to indexed views...
In SQL 2012.A query that joins 2 table, with order by clause doesn't get sorted and the result set is not ordered. This happens when some of the columns in the where criteria are in a unique index which is the index that is used for the join between the 2 tables, and all the columns in the unique index are in the where criteria.In the query plan there is no component for sort.The work around was to drop the unique index, or change it to a non-unique index. Once this was done, the execution plan was changed to add the sort component (even when the index was changed to non-unique and the join was still using this index).
I am really puzzled by an apparent difference between table index key column order and its statistics order. I was under understanding that index statistics mirror index definition. However, in my db 2470 index ordinal definitions match statistics definition but 66 do not. I also can reproduce such discrepancy in 2008 R2, 2012 and 2014.
As per definition,
stats_column_id int
1-based ordinal within set of stats columns
This script duplicates this for me.
BEGIN TRAN GO use tempdb GO CREATE TABLE [dbo].[ItemProperties]( [itmID] [int] NOT NULL, [cpID] [smallint] NOT NULL, [ipuID] [tinyint] NOT NULL,
[Code] ....
The result I get is this:
object_id      stats_name                                     stats_column_list 1525580473 PK_ItemProperties_itmID_ipuID_cpID itmID, cpID, ipuID,
and
object_id      index_name                                     index_column_list 1525580473 PK_ItemProperties_itmID_ipuID_cpID itmID, ipuID, cpID,
Also a query I used to discover this in my db is:
WITH stat AS ( SELECT s.object_id ,s.name as stats_name ,( SELECT c.name + ', ' as [data()] FROM sys.stats_columns as sc
please explain the differences btween this logical & phisicall operations that we can see therir graphical icons in execution plan tab in Management Studio
I've just set up a maintenance plan that backs up all user databases daily and logs hourly. I've just noticed that the plan history is giving the following error -
Database 'BizTalkEDIDb' is not valid to be included in the maintenance plan.
Has anyone seen this before or know how to resolve it?