What is a join and explain different types of joins - Joins are used in queries to explain how different tables are related. - Joins also let you select…
What is Data Warehousing? - Data Warehousing is a process of storing and accessing data from central location for some strate…
What is "correlated subqueries"? - In "correlated subqueries", the result of outer query is passed to the subquery and the…
What are the restrictions applicable while creating views? Views can be created referencing tables and views only in the current database. A view name must not…
Difference between clustered and non-clustered index - Both stored as B-tree structure. The leaf level of a clustered index is the actual data where as …
Explain the use of group by clause - "Group By" is used to derive aggregate values by grouping similar data. Explain the use …
What is sub-query? Sub-query is a query within a Query. Example of sub-query: Select CustId, Custname From Customer Wher…
Explain in brief the cursor optimization tips 1) Close cursor when it is not required. 2) You shouldn’t forget to deallocate cursor after closing …
Explain the cursor types DYNAMIC : It reflects changes happened on the table while scrolling through the row. STATIC : It works…
What is cursor? A Cursor is a database object that represents a result set and is used to manipulate data row by ro…
What is Union and Union All operator? - Union is used to combine distinct records from two tables. - Union all combines all records from t…
Explain DML and DDL statements Data definition language is used to define and manage all attributes and properties of a database. M…
What is denormalization? The process of adding redundant data to get rid of complex join, in order to optimize database perf…
What is normalization? - Normalization is the way of organizing data in a database by removing redundancy and inconsistent…
What are the benifits of normalizing database? - It helps to avoid duplicate entries. - It allows saving storage space. - It enhances the performanc…
Explain the types of relationships in database 1) One-to-one: One to one is implemented using single table by establishing relationship between sa…
What are E-R diagrams? - E-R diagrams, i.e. Entity-Relationship diagram represent relationship between various tables in t…
Define SQL - Structured query language, SQL is an ANSI standard language that provides commands to access and …
Define alternate key There can be a key apart from primary key in a table that can also be a key. This key may or may no…
Define Primary key and Foreign key Define Primary key and Foreign key. - A column or combination of columns that identify a row of data…
