10+ Salasar Services Insurance Brokers Interview Questions and Answers

UNION combines results from two queries, removing duplicates; UNION ALL includes all results, retaining duplicates.

• UNION removes duplicate rows from the result set.

• UNION ALL includes all rows, even duplicates.

• Example of UNION: SELECT column1 FROM table1 UNION SELECT column1 FROM table2;

• Example of UNION ALL: SELECT column1 FROM table1 UNION ALL SELECT column1 FROM table2;

• UNION may be slower due to duplicate removal, while UNION ALL is generally faster.

To find the third highest salary, use SQL queries with ORDER BY and LIMIT or subqueries.

• Use 'SELECT DISTINCT salary FROM employees ORDER BY salary DESC LIMIT 1 OFFSET 2;' to get the third highest salary.

• Alternatively, use a subquery: 'SELECT MAX(salary) FROM employees WHERE salary < (SELECT MAX(salary) FROM employees WHERE salary < (SELECT MAX(salary) FROM employees));'

• Ensure the salary column is indexed for better performance on large datasets.

SQL joins combine rows from two or more tables based on related columns, enabling complex queries and data analysis.

• INNER JOIN: Returns records with matching values in both tables. Example: SELECT * FROM A INNER JOIN B ON A.id = B.id;

• LEFT JOIN (or LEFT OUTER JOIN): Returns all records from the left table and matched records from the right table. Example: SELECT * FROM A LEFT JOIN B ON A.id = B.id;

• RIGHT JOIN (or RIGHT OUTER JOIN): Returns all records from the right table and m...read more

Various join algorithms used in SQL Server include Nested Loop Join, Merge Join, and Hash Join.

• Nested Loop Join: Used when joining small tables or when there is an index on the join columns.

• Merge Join: Used when joining two sorted datasets, typically faster than Nested Loop Join.

• Hash Join: Used when joining large datasets, involves hashing the join columns for efficient matching.

• Example: SELECT * FROM Table1 INNER JOIN Table2 ON Table1.ID = Table2.ID

Different types of joins in SQL include inner join, outer join, left join, and right join. Handling duplicates can be done using DISTINCT keyword or GROUP BY clause.

• Types of joins in SQL: inner join, outer join, left join, right join

• Handling duplicates in SQL: use DISTINCT keyword or GROUP BY clause

• Handling duplicates in Excel: use Remove Duplicates feature

Identifying duplicate data involves using SQL queries or data profiling techniques to find repeated entries in a dataset.

• Use SQL queries with GROUP BY and HAVING clauses to find duplicates. Example: SELECT column_name, COUNT(*) FROM table_name GROUP BY column_name HAVING COUNT(*) > 1.

• Utilize data profiling tools that can automatically detect duplicates based on defined criteria.

• Implement data validation rules during data entry to prevent duplicates from being created.

• Use prog...read more

A stored procedure is a precompiled collection of SQL statements stored in a database for reuse and efficiency.

• Encapsulates complex SQL logic for reuse, e.g., calculating total sales.

• Improves performance by reducing network traffic, e.g., executing multiple queries in one call.

• Enhances security by controlling access to data, e.g., granting execute permissions only.

• Supports parameters for dynamic execution, e.g., passing a customer ID to retrieve specific records.

• Can include e...read more

Research industry standards, functionality needed, security requirements, and compatibility with existing systems.

• Research industry standards to ensure compliance

• Identify required functionality and features

• Consider security requirements and protocols

• Check compatibility with existing systems

• Evaluate documentation and support provided by API providers

User Stories follow a structured format to capture requirements in Agile development.

• Start with a simple, clear statement of the feature

• Include the user role, action, and benefit

• Use the format: As a [user role], I want [action], so that [benefit]

• Break down large stories into smaller, manageable ones

The ER diagram shows the relationships between entities in the application's database.

• The ER diagram displays entities as boxes and relationships as lines connecting them

• Entities represent real-world objects like customers, products, or orders

• Relationships show how entities are connected, such as one-to-one, one-to-many, or many-to-many

• Attributes within entities describe the characteristics of the entity, like name, ID, or date

Data warehousing is the process of collecting, storing, and managing data from various sources for analysis and reporting.

• Data warehousing involves extracting data from multiple sources

• Data is then transformed and loaded into a central repository

• The data can be queried and analyzed for business intelligence purposes

• Examples of data warehousing tools include Oracle Exadata, IBM Netezza, and Microsoft SQL Server

Union combines and removes duplicates, Union All combines all rows including duplicates.

• Union combines the result sets of two or more SELECT statements and removes duplicates

• Union All combines the result sets of two or more SELECT statements including duplicates

• Union is slower than Union All as it involves removing duplicates

A livelock is a situation where two or more processes continuously change their states in response to each other without making any progress.

• Occurs when two or more processes are each waiting for the other to release a resource, preventing any progress

• Similar to a deadlock, but the processes are not blocked - they are simply unable to make progress

• Common in distributed systems where processes communicate over a network

Window functions in SQL are used to perform calculations across a set of table rows related to the current row.

• Window functions are used to calculate values based on a specific subset of rows within a result set.

• They do not cause rows to become grouped into a single output row like aggregate functions.

• Common window functions include ROW_NUMBER(), RANK(), DENSE_RANK(), and NTILE().