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Questions tagged [non-clustered-index]

Non-Clustered Index contains pointers to the data that is stored in the data page. In Non-Clustered Index logical order doesn’t match with physical order of stored data on disk.

Non-Clustered Index contains pointers to the data that is stored in the data page. In Non-Clustered Index logical order doesn’t match with physical order of stored data on disk. Non-clustered index contains index key to the table records in the leaf level. There can be one or more Non-clustered indexes in a table.

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Create nonclustered index with Entity Framework Core 5.0.4 with a GUID primary key

I have this entity class: public class StatusCode { public const String ClassName = nameof(StatusCode); [Key] public Guid UniqueID { get; set; } // Primary Key public Char Level { get; set; } //…
Greg Harris
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By how much do SSDs narrow the performance gap between clustered and non clustered indices?

Most SQL relational databases support the concept of a clustered index in a table. A clustered index, usually implemented as a B-tree, represents the actual records in a given table, physically ordered by that index on disk/storage. One advantage…
Tim Biegeleisen
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Speeding ORDER BY clause with index

I have a query with an ORDER BY clause that is slow due to the table having over 11 million rows. I can speed it up dramatically by adding a clustered index on the column in the ORDER BY clause. However, the software creates the query to order by…
Jonathan Wood
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SQL Server non-clustered index

I have two different queries in SQL Server and I want to clarify how the execution plan would be different, and which of them is more efficient Queries: SELECT * FROM table_name WHERE column < 2 and SELECT column FROM table_name WHERE…
pelopid
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Default index in MS SQL Server

When I use the below query to create index for a column in MS SQL Server create index IX_indexname on tablename(columnname); without mentioning it as clustered or non clustered index, what index will be created? Which is the default index?
Dinesh M
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Reason for the count of non clustered index in Sql Server

Why we have 249 non clustered index in sql server 2005? why not 240 or 300? and the same question for sql server 2008, why 999 ? Why not 800 or 1000?
Zerotoinfinity
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Filtered index vs normal non clustered index

I have 270 million records in a table. Currently I have a non clustered index in it on a date column. 99% of time I use rows with date > 1/1/2008..that means 140 million out of it. I am using SQL server 2008.In this situation will it be beneficial…
Relativity
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What's the effect of including an "include" column in a non-clustered index that's already part of the clustering key?

Suppose I cluster a table on (RetailerID, PurchaseDate, UserID). That's the "clustering key", and clustering keys are always included in all non-clustered…
Triynko
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How to avoid key lookup

My database needs to have GUID's as its primary key as its synced with multiple offline databases so IDENTITY column was not an option as it would lead to collisions in syncing. Since GUID's would have lead to high table fragmentation, we opted to…
user1763470
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Optimize the execution of select

I want optimize this select: Select Dane1, Dane5, Dane6, Dane7 FROM Test INNER JOIN Test2 ON Test.Id=Test2.IdTest WHERE Dane5 > 199850 My database has 2 tables test, test2: test design: Id int ->PRIMARY KEY, Dane1 int, Dane2 int, Dane3 int, Dane4…
Prezes Łukasz
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Improve SQL Server 2005 Query Performance

I have a course search engine and when I try to do a search, it takes too long to show search results. You can try to do a search here http://76.12.87.164/cpd/testperformance.cfm At that page you can also see the database tables and indexes, if…
user366810
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How to create temporary non cluster index on my searching table Columns and remove it after select operation

I have 1 stored procedure which can return more than 1000 of records. I want to Create temporary Non cluster index on my searching table columns as because i have heard that non cluster index will speed up data retrieval (SELECT) operations and slow…
user4155786
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Specifying existing non clustered unique index when defining a primary key constraint

I have a heap table - no clustered index defined - (call it table A), with a unique non clustered index on a non nullable column (call the column ID and the index IX). I would like to use index IX when defining the primary key constraint on column…
Kerneels Roos
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Why is my query doing a clustered index scan when it has an index

I am running a sample database from a SQL Server 2012 training book, learning a bit about indexes so I thought I'd try and see how it works. The table Orders has an index on shippostalcode, so I tried to put that in the where clause, I know there…
sprocket12
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Clustered sorts data physically and non-clustered index too?

CREATE table comp_tb ( a tinyint ) insert into comp_tb values('4') insert into comp_tb values('1') insert into comp_tb values('5') insert into comp_tb values('6') insert into comp_tb values('10') insert into comp_tb values('3') insert into…
Registered User
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