Nonclustered Index
Nov 19, 1999hello!
Is it possible to set nonclustered
index on column with dublicate values?
Thank you,
Alona
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Advantages Of Using Nonclustered Index After Using Clustered Index On One Table
Jul 3, 2006Hi everyone,
When we create a clustered index firstly, and then is it advantageous to create another index which is nonclustered ??
In my opinion, yes it is. Because, since we use clustered index first, our rows are sorted and so while using nonclustered index on this data file, finding adress of the record on this sorted data is really easier than finding adress of the record on unsorted data, is not it ??
Thanks
Clustered Index Or NonClustered Index
Apr 1, 2006Hello I want to learn disparity clustered index or nonclustered index and in queries which one run better.
example
select * from orders where orderID=5
to this query clustered or nonclustered
thanks
CLUSTERED INDEX Or NONCLUSTERED
Feb 20, 2004I have 3 table A, B, C
Table A (15 field, 4 fields indexed and Primary Key) – approximate rows: 50.000 – 60.000
Table B (18 field, 6 fields indexed and Primary Key) – approximate rows: 350.000 – 500.000
Table C (16 filed, 9 fields indexed and Primary Key) – approximate rows: 500.000 – 1.000.000
Structure is something like this:
A (master) --> B (detail) ---> C (sub detail)
On each 3 table is added new record, in table C the record is added after a search in table B.
My question is: Which is the best method? CLUSTERED INDEX or NONCLUSTERED INDEX
Thanks
Sorry for my english
Clustered And Nonclustered Index
Jun 2, 2006when do you use them?
i only know you use clustered when you have million of records. So once the table has been indexed, query statement is able to retrieve the recordset faster.
what about nonclustered?
CREATE NONCLUSTERED INDEX
Jul 6, 2007Hi guys. I have a table named [Check] and need to create an index for CVNumber field. The table has no primary key for the meantime. I tried this script but error occured.
BEGIN TRANSACTION
SET QUOTED_IDENTIFIER ON
GO
SET TRANSACTION ISOLATION LEVEL SERIALIZABLE
GO
COMMIT
BEGIN TRANSACTION
CREATE NONCLUSTERED INDEX IX_Check_1 ON dbo.[Check]
(
CVNumber
) ON [PRIMARY]
GO
COMMIT
Error message:
Server: Msg 3023, Level 16, State 2, Line 3
Backup, CHECKALLOC, bulk copy, SELECT INTO, and file manipulation (such as CREATE FILE) operations on a database must be serialized. Reissue the statement after the current backup, CHECKALLOC, or file manipulation operation is completed.
Server: Msg 3902, Level 16, State 1, Line 1
The COMMIT TRANSACTION request has no corresponding BEGIN TRANSACTION.
Is it because I used the table name Check which is a reserved word for SQL? But I included [ ].
Please help. Thank you.
Composite Nonclustered Index
Jul 18, 2006Hi everyone,
I have some problems on composite nonclustered indexes. I could not exatly understand their logic.
In my opininon, suppose that we have a table called Order and we create a composite nonclustered index on this table for OrderID column and OrderDate column. So I am using this query;
SELECT * FROM Order WHERE OrderID > 12 ORDER BY OrderDate
So in here, I think our first research is based on OrderID and ten after ordering our data pointer according to the OrderID and then our index is converted to an index which is based on OrderDate while performing ordering. So is this correct ??
Would you please explain this ?
Thanks
Is Bookmark In A Nonclustered Index Ordered?
Jul 23, 2005When a nonunique nonclustered index is built on top of a clusteredindex, is it guaranteed that the bookmark in the nonclustered indexwill be kept in the same order as the clustered index?Here's an example to demonstrate my question:CREATE TABLE indextest (col1 int NOT NULL,col2 int NOT NULL,col3int,col4 int)ALTER TABLE indextest ADD PRIMARY KEY CLUSTERED (col1,col2)CREATE INDEX ix_indextest ON indextest (col1,col3)GOINSERT indextest VALUES (1,2,1,1)INSERT indextest VALUES (1,3,2,1)INSERT indextest VALUES (1,4,2,1)INSERT indextest VALUES (2,1,1,1)INSERT indextest VALUES (1,1,1,1)SELECT col1,col2 FROM indextest WHERE col1=1 AND col3=1DROP TABLE indextestThe select statement above is covered by the nonclustered index, sothat index is used. However, the nonclustered index is defined only toensure the ordering of col1 and col3 within the index; col1 and col2follow within the index as the bookmark to the clustered index. When Irun this query, my desired result is to have the records appear in theorder supported by the clustered index:1,11,2As it happens, the result I got was indeed in that order, but I don'tknow if it was mere coincidence, or if the bookmark in the nonclusteredindex is maintained in the same order as the clustered index. If Iwant to ensure the above order, is it sufficient to have thenonclustered index defined as above, or do I need to define it as:create index ix_indextest on indextest (col1,col3,col2)just to be sure that the results are returned in ascending order forcol1,col2? If the two-column index is sufficient, is it guaranteed tostill be sufficient in SQL2005 and future versions of SQL Server, or amI better off adding the third column just to be safe?Thank you,--Dennis Culley
View 4 Replies View RelatedDB Design :: Nonclustered Index Create
Aug 27, 2015I have table which having clustered index based on column (A,B,C,D,E,F).Now my query based on B,D,F. e.g: where b='Test1' and D='test2' and F='test3' Now Execution plan ask to create non clustered index with (B,D,F) column.is it make any sense to create non clustered index where clustered already available.
View 4 Replies View RelatedNonClustered Index Page Splitting
Dec 3, 2007
I am attempting to understand the behaviour of a nonclustered index in regards to page splitting.
If I had the following table:-
Col1, Col2, Value
This table has a Clustered index on Col1, Col2 and a NonClustered index on Col2 and include Col1, Values.
If inserts into Col1 were causing page splits in the Clustered index, what are the effects on the NonClustered index?
I am attempting to understand what happens to the NonClustered index in this scenario so that I can make a decision on what fillfactor to use.
Table1(col1) Clustred , Table1(col1,col2,col3) Nonclustered Index , Which One To Keep ?
Jun 27, 2007For a table 'table1' in sqlserver 2000,
table1(col1) is clustred index 'Ix1' and table1(col1,col2,col3) is nonclustered index 'ix2'
is not tabel1(col1) 'ix1' a duplicate/redundant index ?
which index should be retained ?
or should both indexes remain on the OLTP table ?
Thanks a lot in advance.
Clustered Vs Nonclustered PK
Jul 16, 2007Ok, let me try to set the stage.
Between 2m and 5m inserts per day. NO UPDATES.
Table has a 4 part primary key. All BigInt data types. Key value 1 and 2 have a range between 1 and 100. Key values 3 and 4 are auto incrementing values (forign key values) from other tables.
Space is an issue, so we have chosen not to have an additional column for a counter field for the PK. (We would never use the field for querying.)
Users complained of query speeds, so we added a couple non clustered indexs. This brought up the query speeds a lot. But of course it slowed down the input speed a bit. Nothing dramatic, but enough so we could tell.
Now the users was to increase the amount of data by about 5X. Obviosly I'm somewhat concerend, as SQL is already spending a lot of the day pegged.
So, in looking around, since the new indexes seem to be the most help in querying, I'm thinking of dropping the PK back to a nonclustered index, so I can get rid of the over head of restructring the data table on every insert. Then maybe making one of the other indexes the clustered index. (only 2 columns in this index)
Thoughts?
Nonclustered Indexes Quickie
Jul 31, 2007Hi You know when you reread something you've read many times and a penny suddenly seems to drop and you realise that you probably just never quite got it afterall? If creating a nonclustered index with no includes statement it is totally pointless to specificy a fillfactor other than 0 or 100 if you do not also use the PAD_INDEX option? Thought I'd make it a poll just for the hell of it.:)
View 5 Replies View RelatedScan Density Of Nonclustered Indexes
Oct 23, 1999A few days after droping and recreating noclustered indexes on a large table, scan density of most indexes falls below 20%. Only a few number of rows has deleted. Update operation didn't update these keys and there was a lot of inserts. Could anyone explain why are indexes fragmented so much?
View 2 Replies View RelatedSQL Server 2012 :: Nonclustered Indexes On Bit Flags
Mar 24, 2015I have a scenario where I have 3 columns and all 3 of them are used in the where clauses of simple queries or ones having joins .
TABLE(
Column1 int
FLAG1 bit
FLAG2 bit
)
Sample queries :
Select * from TABLE where FLAG1 =1 and FLAG2 =0
(Any combination of these flags)
Select * from TABLE inner join SOMEOTHERTABLE on
TABLE.Column1 = SOMEOTHERTABLE .Column1
where FLAG1 =1 and FLAG2 =0
( any join and combination of flags)
Questions :
What would be the best nonclustered index strategy :
Column1 as the index key including FLAG1 and FLAG2
or
Column1,FLAG1 and FLAG2 in the index key
Points to note :
The queries are part of an ETL process and are used to track new records vs old records. The Flags switch states within the same job . So if we are creating an index on all 3 columns, the index has to be reorganized more than once based on the flag states. If we keep them in the include list , then its only about updating the leaf data with the latest flag values.
On the other hand, an index on all 3 columns will result in an index Seek alone , where as for the included list , there will be an index seek and a predicate .
Does the predicate cause more overhead than reorganizing the index or is it the opposite ?
Difference Between Index Seek && Index Scan && Index Lookup Operations?
Oct 20, 2006please explain the differences btween this logical & phisicall operations that we can see therir graphical icons in execution plan tab in Management Studio
thank you in advance
SQL 2012 :: Full Text Index How To Make It NOT To Index Embedded Or Attached Documents
Sep 30, 2015I am using Full Text Index to index emails stored in BLOB column in a table. Index process parses stored emails, and, if there is one or more files attached to the email these documents get indexed too. In result when I'm querying the full text index for a word or phrase I am getting reference to the email containing the word of phrase if interest if the word was used in the email body OR if it was used in any document attached to the email.
How to distinguish in a Full Text query that the result came from an embedded document rather than from "main" document? Or if that's not possible how to disable indexing of embedded documents?
My goal is either to give a user an option if he or she wants to search emails (email bodies only) OR emails AND documents attached to them, or at least clearly indicate in the returned result the real source where the word or phrase has been found.
Clustered Index On Client_ID+ORderNO+OrdersubNo, If I Create 3 Noncluster Index On Said Column Will It Imporve Performance
Dec 5, 2007
Dear All.
We had Teradata 4700 SMP. We have moved data from TD to MS_SQL SERVER 2003. records are 19.65 Millions.
table is >> Order_Dtl
Columns are:-
Client_ID varchar 10
Order_ID varchar 50
Order_Sub_ID decimal
.....
...
..
.
Pk is (ClientID+OrderId+OrderSubID)
Web Base application or PDA devices use to initiate the order from all over the country. The issue is this table is not Partioned but good HP with 30 GB RAM is installed. this is main table that receive 18,0000 hits or more. All brokers and users are using this table to see the status of their order.
The always search by OrderID, or ClientID or order_SubNo, or enter any two like (Client_ID+Order_Sub_ID) or any combination.
Query takes to much time when ever server receive more querys. some orther indexes are also created on the same table like (OrderDate, OrdCreate Date and Status)
My Question are:-
Q1. IF Person "A" query to DB on Client_ID, then what Index will use ? (If any one do Query on any two combination like Client_ID+Order_ID, So what index will be uesd.? How does MS-SQL SERVER deal with these kind of issues.?
Q2. If i create 3 more indexes on ClientID, ORderID and OrdersubID. will this improve the performance of query.if person "A" search record on orderNo so what index will be used. (Mind it their would be 3 seprate indexes for Each PK columns) and composite-Clustered index is also available.?
Q3. I want to check what indexes has been used? on what search?
Q4. How can i check what table was populated when, or last date of update (DML)?
My Limitation is i Dont Create a Partioned table. I dont have permission to do it.
In Teradata we had more than 4 tb record of CRM data with no issue. i am not new baby in db line but not expert in sql server 2003.
I am thank u to all who read or reply.
Arshad
Manager Database
Esoulconsultancy.com
(Teradata Master)
10g OCP
Integration Services :: Rebuild Index / Refresh Index And Stats Improves Ssis Package Performance
Oct 28, 2015My SSIS package is running very slow taking so much time to execute, One task is taking 2hr for inserting 100k records, i have disabled unused index still it is taking time.I am rebuilding/Refreshing indexes and stats once in month if i try to execute on daily basis will it improve my SSIS Package performance?Â
View 2 Replies View RelatedIndex Was Out Of Range. Must Be Non-negative And Less Than The Size Of The Collection. Parameter Name: Index
Jan 22, 2006Keep getting this error when positioning to the last page of a report.
Using Server 2003...SqlRpt Svcs 2000 sp2
Detail error msg:
Exception of type Microsoft.ReportingServices.ReportRendering.ReportRenderingException was thrown. (rrRenderingError) Get Online Help
Exception of type Microsoft.ReportingServices.ReportRendering.ReportRenderingException was thrown.
Index was out of range. Must be non-negative and less than the size of the collection. Parameter name: index
Anyone have any suggestions? Any way to find out what collection is blowing?...or where parameter name: index comes from?
Index Table1 And Select For 647.600 Records.. It Is So Slow.. But I Have No Index :)???
Jun 20, 2008hello friends
i have table1 and 200 coulumn of table1 :) i have 647.600 records. i entered my records to table1 with for step to code lines in one day :)
i select category1 category2 and category3 with select code but i have just one index.. it is productnumber and it is primarykey..So my select code lines is so slow.. it is 7-9 second.. how can i select in 0.1 second ? Should i create index for category1 and category2 and category3 ? But i dont know create index.. My select code lines is below.. Could you learn me and show me index for it ?? or Could you learn me and show me fast Select code lines and index or etc ??? Also my search code line have a dangerous releated to attaching table1 with hackers :)
cheersi send 3 value of treview1 node and childnode and child.childnode to below page.aspx :)
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
If Not Me.IsPostBack Then
If Request("TextBox1") IsNot Nothing ThenTextBox1.Text = Request("TextBox1")
End If
If Request("TextBox2") IsNot Nothing ThenTextBox2.Text = Request("TextBox2")
End If
If Request("TextBox3") IsNot Nothing ThenTextBox3.Text = Request("TextBox3")
End If
End If
Dim searchword As String
If Request("TextBox3") = "" And Request("TextBox2") = "" Then
searchword = "Select * from urunlistesi where kategori= '" & Request("TextBox1") & "'"
End If
If Request("TextBox3") = "" Then
searchword = "Select * from urunlistesi where kategori= '" & Request("TextBox1") & "' and kategori1= '" & Request("TextBox2") & "'"
End If
If Request("TextBox3") <> "" And Request("TextBox2") <> "" And Request("TextBox1") <> "" Then
searchword = "Select * from urunlistesi where kategori= '" & Request("TextBox1") & "' and kategori1= '" & Request("TextBox2") & "' and kategori2= '" & Request("TextBox3") & "'"
End If
SqlDataSource1.SelectCommand = searchword
End Sub
The Index Entry For Row ID Was Not Found In Index ID 3, Of Table 357576312
Jul 9, 2004Hi,
I'm running a merge replication on a sql2k machine to 6 sql2k subscribers.
Since a few day's only one of the merge agents fail's with the following error:
The merge process could not retrieve generation information at the 'Subscriber'.
The index entry for row ID was not found in index ID 3, of table 357576312, in database 'PBB006'.
All DBCC CHECKDB command's return 0 errors :confused:
I'm not sure if the table that's referred to in the message is on the distribution side or the subscribers side? A select * from sysobjects where id=357576312 gives different results on both sides . .
Any ideas as to what is causing this error?
SQL 2012 :: Clustered Index Key Order In NC Index
Mar 5, 2015I have a clustered index that consists of 3 int columns in this order: DateKey, LocationKey, ItemKey (there are many other columns in this data warehouse table such as quantities, prices, etc.).
Now I want to add a non-clustered index on just one of the other columns, say LocationKey, like this:
CREATE INDEX IX_test on TableName (LocationKey)
I understand that the clustered index keys will also be added as key columns to any NC indexes. So, in this case the NC index will also get the other two columns from the clustered index added as key columns. But, in what order will they be added?
Will the resulting index keys on this new NC index effectively be:
LocationKey, DateKey, ItemKey
OR
LocationKey, ItemKey, DateKey
Do the clustering keys get added to a NC index in the same order as they are defined in the clustered index?
Clustered Index Vs. Full Text Index
Jun 18, 2008Quick question about the primary purpose of Full Text Index vs. Clustered Index.
The Full Text Index has the purpose of being accessible outside of the database so users can query the tables and columns it needs while being linked to other databases and tables within the SQL Server instance.
Is the Full Text Index similar to the global variable in programming where the scope lies outside of the tables and database itself?
I understand the clustered index is created for each table and most likely accessed within the user schema who have access to the database.
Is this correct?
I am kind of confused on why you would use full text index as opposed to clustered index.
Thank you
Goldmember
Index/performance Index For SELECT.... IN Statement
Sep 10, 2007
Hi All,
I 'm working to improve some sql performance.
One of the major syntax inside the SELECT statment is ..
WHERE FIELDA IN (SELECT PARAVALUE FROM PARATABLE WHERE SESSIONID = "XXXXX" AND PARATYPE='A') AND
WHERE FIELDB IN (SELECT PARAVALUE FROM PARATABLE WHERE SESSIONID = "XXXXX" AND PARATYPE='B') AND
WHERE FIELDC IN (SELECT PARAVALUE FROM PARATABLE WHERE SESSIONID = "XXXXX" AND PARATYPE='C') AND
WHERE FIELDD IN (SELECT PARAVALUE FROM PARATABLE WHERE SESSIONID = "XXXXX" AND PARATYPE='D') AND
WHERE FIELDE IN (SELECT PARAVALUE FROM PARATABLE WHERE SESSIONID = "XXXXX" AND PARATYPE='E') AND
WHERE FIELDF IN (SELECT PARAVALUE FROM PARATABLE WHERE SESSIONID = "XXXXX" AND PARATYPE='F')
(It's to compare the field content with some user input parameter inside a parameter table... )
I think properly is that the SELECT ... IN is causing much slowness in the sql statement. I have indexed FIELDA , FIELDB, FILEDC etc and those PARAVALUE and PARATYPE in the PARATABLE table. But perfromance is still slow and execution takes >20 seconds for 200000 rows of records.
Do any one know if still any chance to improvide the performance like this?
Much Thanks,
Andy
Index Internals - Last Time Index Was Rebuilt?
Apr 17, 2007I'm trying to find whether there is a dmv or system view that can help me see the last time an index was rebuilt or created. Assuming I rebuilt an index using tsql commands (not a job with a history), is there a way to find out the last time that index was rebuilt?
Thanks much.
Index Scan Vs Index Seek
Mar 1, 2004I have a really strange problem.
I execute this query:
declare @cid int
set @cid = 2003227
select * from sales s, product p where p.product_Id = s.product_Id and customer_id = @cid
select * from sales s, product p where p.product_Id = s.product_Id and customer_id = @cid or @cid = 0
3 Million rows in sales, 120000 in product.
The first does and index seek, the second an index scan.
The execution plan reports that the scan takes 99.87% of the cost, and the seek takes 0.13%
This problem obviously gets worse the bigger the dataset / query /etc.
The reason I query this, is because it never used to take this long to do index scans. Is there something i can change, something i can fix?
Any help would be appreciated.
Josh
Reorganize Index And Rebuild Index ??
Mar 18, 2008Hi,
I just want to know whether any advantage or disadvantage
in doing Reorganize Index And Rebuild Index ....
Plz do comment on this ASAP !!!!
Thanks in advance
Regards
Arv
Reorganize Index And Rebuild Index
Mar 18, 2008Hi,
I just want to know whether any advantage or disadvantage
in doing Reorganize Index And Rebuild Index ....
Plz do comment on this ASAP !!!!
Thanks in advance
Regards
Arv
Simple Query Chooses Clustered Index Scan Instead Of Clustered Index Seek
Nov 14, 2006the query:
SELECT a.AssetGuid, a.Name, a.LocationGuid
FROM Asset a WHERE a.AssociationGuid IN (
SELECT ada.DataAssociationGuid FROM AssociationDataAssociation ada
WHERE ada.AssociationGuid = '568B40AD-5133-4237-9F3C-F8EA9D472662')
takes 30-60 seconds to run on my machine, due to a clustered index scan on our an index on asset [about half a million rows]. For this particular association less than 50 rows are returned.
expanding the inner select into a list of guids the query runs instantly:
SELECT a.AssetGuid, a.Name, a.LocationGuid
FROM Asset a WHERE a.AssociationGuid IN (
'0F9C1654-9FAC-45FC-9997-5EBDAD21A4B4',
'52C616C0-C4C5-45F4-B691-7FA83462CA34',
'C95A6669-D6D1-460A-BC2F-C0F6756A234D')
It runs instantly because of doing a clustered index seek [on the same index as the previous query] instead of a scan. The index in question IX_Asset_AssociationGuid is a nonclustered index on Asset.AssociationGuid.
The tables involved:
Asset, represents an asset. Primary key is AssetGuid, there is an index/FK on Asset.AssociationGuid. The asset table has 28 columns or so...
Association, kind of like a place, associations exist in a tree where one association can contain any number of child associations. Each association has a ParentAssociationGuid pointing to its parent. Only leaf associations contain assets.
AssociationDataAssociation, a table consisting of two columns, AssociationGuid, DataAssociationGuid. This is a table used to quickly find leaf associations [DataAssociationGuid] beneath a particular association [AssociationGuid]. In the above case the inner select () returns 3 rows.
I'd include .sqlplan files or screenshots, but I don't see a way to attach them.
I understand I can specify to use the index manually [and this also runs instantly], but for such a simple query it is peculiar it is necesscary. This is the query with the index specified manually:
SELECT a.AssetGuid, a.Name, a.LocationGuid
FROM Asset a WITH (INDEX (IX_Asset_AssociationGuid)) WHERE
a.AssociationGuid IN (
SELECT ada.DataAssociationGuid FROM AssociationDataAssociation ada
WHERE ada.AssociationGuid = '568B40AD-5133-4237-9F3C-F8EA9D472662')
To repeat/clarify my question, why might this not be doing a clustered index seek with the first query?
Change Nc-index To C-index?
Jun 29, 2004Found out a while back that my facts-tabel has an non-clustered index on its facts_id. In a bunch of procedures an update is executed against a facts_id unfortunately on it's facts-table. I was wondering if changing it into a clustered index is worth the effort / would make sense considering a +110 million facts and re-indexing the other indexes as well? Facts are loaded sequentially, so I would suspect them facts are in the ordered already?
thanx,
Index Seek, Index Scan, Table Scan
Oct 4, 2007
Hey,
what is the difference between Table Scan und Index Scan?
I find no difitions in the internet
Finchen
What Is Table Scan, Index Scan And Index Seek??
Sep 21, 2007Hi,
I want to know wht is a
TABLE SCAN
INDEX SCAN
INDEX SEEKand When they are used, Wht is the difference between all these.????