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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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nonclustered index on join

I have been wondering if having nonclustered index on the join would improve performance?? like INNER JOIN FaceList fl ON fl.FaceListID = flf.FaceListID in above join can I get performance benefit when I have nonclustered index on FaceListID since…
Sandip Bantawa
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Why would the Primary Key NOT BE a Clustered Index and another Index BE Clustered?

I was reviewing indexes on our SQL Server database today and noticed a relatively small (very old) table (3250 rows) that has a column of type varbinary(max) for image data. The Primary Key is a Non-Clustered Index, and there is another index (on…
Narnian
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Can Clustered index change dynamic SQL statement behavior and return different results?

Possible Duplicate: ORDER BY suddenly conflicting with VARCHAR concatenation in TSQL recently, I found create clustered index in one table and this clustered index changed the results of a dynamic SQL statement. When the table have clustered…
user1766928
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If a table has 'id' column as it's clustered index, is there any benefit in adding 'id' column as an included column in any other non-clustered index

If a table has 'id' (the primary key) column as its clustered index, is there any benefit in adding 'id' column as an included column in any other non-clustered index in Microsoft SQLServer? eg:- Table…
Priyal
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Preventing to create non-clustered index in EF Core 3.1 code-first

In EF Core, by default, it creates a non-clustered index for a foreign key for code-first approach. I want to prevent creating non-clustered index on the foreign key in the EF Core 3.1. In Entity Framework "classic" (not Core), I could to do it like…
Rousonur Jaman
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SQL Server parameterized query does not use Non Clustered Filtered

I defined a non clustered index with Include and Filter on Students table. The SQL Server version is 2017. Students table definition: CREATE TABLE [dbo].[Students] ( [Id] [INT] IDENTITY(1,1) NOT NULL, [Name] [NVARCHAR](50) NOT NULL, …
Mohammad Akbari
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Best practice on sql update statement on NCI dateKey in large Fact table

I have a 55Gb Fact table where I have to delete some records which later on can be reverted back. Number of deleted records vary between 10 to 100 thousand. Currently my delete strategy is based on this: I update the dateKey for the records to be…
BumbleBee
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How to combine Index and Columnstore Index?

I am confused to implement best practice, I have a table with a lot of fields which each of them need to be aggregated for analytics and reporting purposes, but sometimes we also require to get row basis records. Would that be better to implement…
Alfin E. R.
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What is the max varchar length for creating non-clustered index in sql server?

Creating a non-clustered index on columns of type varchar(max) is not allowed in SQL Server. So, what is the maximum varchar length that a non-clustered index be created on?
Simple Code
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In Entity Framework code-first, why are primary keys always stored as clustered indexes?

I'm learning more about indexes in general, and clustered indexes in particular. In this article by Markus Winand, he makes an excellent case for not using the primary key of a table as the clustering key. He stresses index-only scans over using…
Winks
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Table index design

I would like to add index(s) to my table. I am looking for general ideas how to add more indexes to a table. Other than the PK clustered. I would like to know what to look for when I am doing this. So, my example: This table (let's call it TASK…
Ash
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Non Clustered Index not working sql server

I have a table that doesn't have any primary key. data is already there. I have made a non clustered index. but when i run query, actual execution plan is not showing index scanning. I think non clustered index is not working. what could be the…
Mohan Sharma
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Create clustered or nonclustered index on 1 million rows table for LIKE query?

I have a database table with postal codes, city, long, lat, province. I have one use for this table which is to return suggested codes (plus city and province) for an autocomplete widget. city and postalcode make up a unique record. I am starting…
billy jean
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Why is there no heap rid present in the unique non-clustered index root page but is present in root page of non-unique non clustered index?

I am doing some analysis and trying to gather some understanding of unique and non-unique non clustered indexes on SQL Server 2008 ? Following a technical blog,I did the following. USE TEST CREATE TABLE "CustomersHeap" ( …
userx
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What happens when a nonclustered index is deleted?

What happens on the SQL Server engine side when I'm deleting an index from one of my tables? Details: I have a database running into production. In this database, I have a query that creates deadlocks on a regular basis. I've found the query…
Andy M
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