In this blog post, you are going to find a list of top 25 SQL interview questions and answers about indexes which have been often asked.
Through this article, we’ll learn what indexes are, why to use them, how to create them, and when to avoid them. The concept of indexes is mostly asked in the interviews which are focused on SQL…
Clustered vs Nonclustered Indexes in SQL The difference between Clustered and Nonclustered indexin a relational database is one of the most popular SQL interview questions almost as popular as theprimary key vs unique key, thedifference between truncate and delete, andcorrelated vs noncorrelated su...
Related posts: Designing effective SQL Server non-clustered indexes The benefits, costs, and documentation of database constraints Overview of Non-Clustered indexes in SQL Server Top 25 SQL interview questions and answers about indexes Designing effective SQL Server clustered indexesIndexes...
The CREATE INDEX Command in SQL The basic syntax ofCREATE INDEXis as follows: CREATE INDEX index_name ON table_name;Single-Column IndexesA single-column index is one that is created based on only one table column. The basic syntax is as follows: CREATE INDEX index_name ON table_name (col...
SQL - BOOLEAN (BIT) Operator SQL - LIKE Operator SQL - IN Operator SQL - ANY, ALL Operators SQL - EXISTS Operator SQL - CASE SQL - NOT Operator SQL - NOT EQUAL SQL - IS NULL SQL - IS NOT NULL SQL - NOT NULL SQL - BETWEEN Operator ...
The above query will not use the index as we are trying to find all the rows in the table and we don’t have a where clause in the query See alsoSQL Tuning Set in Oracle Query 3 select * from emp where dept_no =5; The above query will not use the index as the where clause ...
Categories:Indexes,SQL ErrorsTags:Indexed View,Materialized View,SQL Views ColumnStore Indexes evolution from SQL Server 2012, 2014 to 2016 4 comments ColumnStore Indexeswere first introduced in SQL Server 2012, and this created a new way to store and retrieve the Index or Table data in an effici...
a table column (where the index is defined on).It can be added to single or multiple columns of a table. If it is added to a single column, the values of that column must be unique. But if it is added to multiple columns, the combination of values in these columns must be unique...
A common DBA job interview question is to ask the candidate the difference between a clustered and nonclustered index, as indexes are a fundamental data storage technology in SQL Server. A clustered index is the underlying table, stored in sorted order based on the key value. There can only ...