A table typically has a column or combination of columns that contain values that uniquely identify each row in the table. This column, or columns, is called the primary key (PK) of the table and enforces the entity integrity of the table. Because primary key constraints guarantee unique data, they are frequently defined on an identity column. They are optional. Refer to Microsoft Doc:

https://docs.microsoft.com/en-us/sql/relational-databases/tables/primary-and-foreign-key-constraints?view=sql-server-ver15

Azure Databricks has several features, and one includes a complete ML platform where you can build, train and test models. Refer to Microsoft Doc:

https://docs.microsoft.com/en-us/azure/databricks/scenarios/what-is-azure-databricks

By default, your Azure Cosmos account is accessible from internet, as long as the request is accompanied by a valid authorization token. To configure IP policy-based access control, the user must provide the set of IP addresses or IP address ranges in CIDR (Classless Inter-Domain Routing) form to be included as the allowed list of client IPs to access a given Azure Cosmos account. Once this configuration is applied, any requests originating from machines outside this allowed list receive 403 (Forbidden) response. Disabling access to the public network may also be effective, but that eliminates access entirely and does not control access to a select group of people. Refer to Microsoft Doc:

https://docs.microsoft.com/en-us/azure/cosmos-db/how-to-configure-firewall

Unburden users of having to memorize credentials for different apps or reusing weak passwords, increasing the risk of data breach. With Azure AD, users can conveniently access all their apps with SSO from any location, on any device, from a centralized and branded portal for a simplified user experience and better productivity. Refer to Microsoft Doc:

https://docs.microsoft.com/en-us/azure/storage/common/storage-auth-aad

In Azure, all newly created databases are encrypted by default and the database encryption key is protected by a built-in server certificate. Certificate maintenance and rotation are managed by the service and require no input from the user. Customers who prefer to take control of the encryption keys can manage the keys in Azure Key Vault. Refer to Microsoft Doc:

https://docs.microsoft.com/en-us/sql/relational-databases/security/encryption/transparent-data-encryption?view=sql-server-ver15

Azure Table Storage is limited to the size of an Azure Storage account, which is generally 5 PB in most places. Refer to Microsoft Doc:

https://docs.microsoft.com/en-us/azure/storage/tables/table-storage-overview

Dynamic data masking (DDM) limits sensitive data exposure by masking it to non-privileged users. It can be used to greatly simplify the design and coding of security in your application. Dynamic data masking helps prevent unauthorized access to sensitive data by enabling customers to specify how much sensitive data to reveal with minimal impact on the application layer. DDM can be configured on designated database fields to hide sensitive data in the result sets of queries. With DDM the data in the database is not changed. DDM is easy to use with existing applications, since masking rules are applied in the query results. Many applications can mask sensitive data without modifying existing queries. Refer to Microsoft Doc:

https://docs.microsoft.com/en-us/sql/relational-databases/security/dynamic-data-masking?view=sql-server-ver15

Cosmos DB is charged based on the following metrics: Provisioned throughput, number of regions, number of availability zones, consumed storage Refer to Microsoft Doc:

https://azure.microsoft.com/en-us/pricing/details/cosmos-db/

Cosmos DB Table API offers single-digit millisecond latency for reads and writes, backed with <10 ms latency for reads and writes at the 99th percentile, at any scale, anywhere in the world. It is not less expensive than table storage. They both offer an SLA, and are both programmable. Refer to Microsoft Doc:

https://docs.microsoft.com/en-us/azure/cosmos-db/table-support?toc=https%3A%2F%2Fdocs.microsoft.com%2Fen-us%2Fazure%2Fstorage%2Ftables%2Ftoc.json&bc=https%3A%2F%2Fdocs.microsoft.com%2Fen-us%2Fazure%2Fbread%2Ftoc.json

The management of transactional data using computer systems is referred to as online transaction processing (OLTP). OLTP systems record business interactions as they occur in the day-to-day operation of the organization, and support querying of this data to make inferences. Refer to Microsoft Doc:

https://docs.microsoft.com/en-us/azure/architecture/data-guide/relational-data/online-transaction-processing