Stored procedure execution
You can use the SQL Server Management Studio (SSMS) user interface or Transact-SQL in an SSMS query window to execute a stored procedure. Always use the latest version of SSMS.
Use SQL Server Management Studio
Step 1: In Object Explorer, connect to an instance of SQL Server or Azure SQL Database [here sql12345678], expand that instance, and then expand Databases.
Step 2: Expand the database that you want [Here first db1], expand Programmability, and then expand Stored Procedures.
Step 3: Right-click the stored procedure that you want to run [Here: ALTER DATABASE SCOPED CONFIGURATION] and select Execute Stored Procedure.
Step 4: Add parameter: QUERY_OPTIMIZER_HOTFIXES = ON
Step 5: Select OK to execute the stored procedure. If the stored procedure doesn't have any parameters, just select OK.
Step 6: Repeated step 2 to step 5 for db2.
Note: The default approach that SQL Server uses for the query optimizer enables any fixes for the latest database compatibility level for a given product release. This means any fixes for the query optimizer will be used up to the compatibility level of the database, but any hotfixes beyond that compatibility level will not be used. Microsoft provides an option to enable query optimizer hotfixes using the scoped configuration QUERY_OPTIMIZER_HOTFIXES.
Use the following command to enable optimizer hotfixes:
ALTER DATABASE SCOPED CONFIGURATION QUERY_OPTIMIZER_HOTFIXES = ON;
This command configures the database to use all query optimizer hotfixes. For example, optimizations that were included in a recent database cumulative update will apply if the administrator has altered the scope to include query optimizer hotfixes. Using QUERY_OPTIMIZER_HOTFIXES applies at the database level, meaning the change would have to be made for each database.
Reference:
https://infohub.delltechnologies.com/en-US/l/performance-best-practices-4/sql-server-2019-query-optimizer-hotfixes
https://learn.microsoft.com/en-us/sql/t-sql/statements/alter-database-scoped-configuration-transact-sql

Explanation:
Step 1: Create a column master key
Create a column master key metadata entry before you create a column encryption key metadata entry in the database and before any column in the database can be encrypted using Always Encrypted.
Step 2: Create a column encryption key.
Step 3: Encrypt the Salary column by using the randomized encryption type. Randomized encryption uses a method that encrypts data in a less predictable manner. Randomized encryption is more secure, but prevents searching, grouping, indexing, and joining on encrypted columns.
Note: A column encryption key metadata object contains one or two encrypted values of a column encryption key that is used to encrypt data in a column. Each value is encrypted using a column master key.
Incorrect Answers:
Deterministic encryption.
Deterministic encryption always generates the same encrypted value for any given plain text value. Using deterministic encryption allows point lookups, equality joins, grouping and indexing on encrypted columns. However, it may also allow unauthorized users to guess information about encrypted values by examining patterns in the encrypted column, especially if there's a small set of possible encrypted values, such as True/False, or North/South/East/West region.
Reference:
https://docs.microsoft.com/en-us/sql/relational-databases/security/encryption/always-encrypted- database-engine

The rows per distribution can vary up to 10% without a noticeable impact on performance. Here the distribution varies more than 10%. It is skewed.
Note: SHOWSPACEUSED displays the number of rows, disk space reserved, and disk space used for a specific table, or for all tables in a Azure Synapse Analytics or Parallel Data Warehouse database.
This is a very quick and simple way to see the number of table rows that are stored in each of the
60 distributions of your database. Remember that for the most balanced performance, the rows in your distributed table should be spread evenly across all the distributions.
ROUND_ROBIN distributed tables should not be skewed. Data is distributed evenly across the nodes by design.
Reference:
https://docs.microsoft.com/en-us/azure/synapse-analytics/sql-data-warehouse/sql-data- warehouse-tables-distribute
https://github.com/rgl/azure-content/blob/master/articles/sql-data-warehouse/sql-data-warehouse- manage-distributed-data-skew.md