DBA / Database

What is the difference between synchronous and asynchronous replication in Always On?

Which grant is used to authorize the execution of a procedure?

How do you understand that these specific indexes on these columns will help achieve performant queries? How do you determine high selectivity?

Have you ever had to automate processes? How did you identify slow queries and how was the optimization carried out?

What are key columns and INCLUDE columns in an index? How to use them correctly?

If a user only needs to execute a stored procedure and nothing else, what permissions should be granted to them?

Among the listed query types (SELECT, INSERT, UPDATE, DELETE), which ones speed up indexes and which ones slow them down?

Tell me more about database security: users, logins, permissions — what did you do at the user level?

What challenges were encountered during the creation of the Always On high availability cluster?

If a query has many conditions (for example, 10 columns in WHERE and JOIN) — what index would you create to improve performance?

How did you ensure the security of your data? What methods did you use?

Explain conceptually how indexes work in SQL. What types of database queries exist?

When monitoring performance, what else did you pay attention to besides slow queries? (CPU, I/O operations)

How to configure indexes in PostgreSQL to ensure fast search across all keys in a table?

Tell me about indexes: when you create them, when it is good, and when it is bad?

How did you manage user access rights to the database? How did you create user groups and assign permissions?

How many clustered indexes can be on a single table and why?

How have you used data encryption? In what situations and for what data?

Tell me about the All-in-one approach in the project: did you create it yourself, when was it used, how many were there?