1) What is the difference between primary key and unique key?
Primary key uniquely identifies a row. Unique keys are created in columns that will the unique row values. Primary key is unique and not null however unique key can have null values
2) Why are you considering AWS while you have current job as DBA?
This is a very common interpersonal question. You can answer whatever you think of as the answer. But provide an answer that discusses advantage of cloud over on-perm systems. Also, mention that databases in future will be 100% hosted in cloud
3) Why AWS instead of oracle cloud or azure environment?
If your current database profile is oracle DBA, SQL Server DBA the companies that have designed, developed, marketed your databases have their properitor platform for hosting the databases in cloud. To choose AWS over the other vendors major reason is that AWS is a decade old firm , growing extremely fast, stable that is much needed for sustainability of enterprise businesses. They cant choose a vendor for price reasons and waste money on migration projects later
4) What is cloud computing?
This is a very common question that will be part of not only cloud dba but also other cloud support roles. Cloud computing in plain terms is migration of your data center to be taken care of by Amazon
5) What are the many different AWS services supporting databases?
AWS RDS the relational database service supports many databases like mysql, postgresql, oracle, sql server and many more. Amazon dynamodb is popular nosql database. Amazon aurora comes in mysql as well as postgressql flavors that is developed, currently heavily marketed by amazon
6) What is DMS?
The data migration service is a GUI from amazon that supports migration of current databases onto AWS cloud Aurora database. Interestingly feasibility , problems that could be encountered during migration including packages, objects that could be impacted post-upgrade will be listed while making use of DMS. This tool is used for migration of databases