41 What are indexes? What are B-Trees? Index makes your search faster. So defining indexes to your database will make your search faster.Most of the indexing fundamentals use “B-Tree” or “Balanced-Tree” principle. It’s not a principle that is something is created by SQL Server or ORACLE but is a mathematical derived fundamental.In order that “B-tree”
31 Can you explain the SELECT INTO Statement? SELECT INTO statement is used mostly to create backups. The below SQL backsup the Employee table in to the EmployeeBackUp table. One point to be noted is that the structure of pcdsEmployeeBackup and pcdsEmployee table should be same. SELECT * INTO pcdsEmployeeBackup FROM pcdsEmployee 32 What is
21 How to select the first record in a given set of rows? Select top 1 * from sales.salesperson 22 What is the default “-SORT ” order for a SQL? ASCENDING 23 What is a self-join? If we want to join two instances of the same table we can use self-join. 24 What’s the difference
11 What are DML and DDL statements? DML stands for Data Manipulation Statements. They update data values in table. Below are the most important DDL statements:- =>SELECT – gets data from a database table => UPDATE – updates data in a table => DELETE – deletes data from a database table => INSERT INTO –
1 What is database or database management systems (DBMS)? and – What’s the difference between file and database? Can files qualify as a database? Database provides a systematic and organized way of storing, managing and retrieving from collection of logically related information. Secondly the information has to be persistent, that means even after the application