Essential Multi-Tenant Database Design Approaches Quiz Quiz

Explore fundamental multi-tenant database design approaches, distinguishing between key strategies like shared and isolated schemas. This quiz helps clarify important concepts and considerations in multi-tenancy architecture for scalable, secure applications.

1. Definition of Multi-Tenancy

   Which description best defines a multi-tenant database architecture?

   1. A database system serving multiple clients (tenants) using a single instance or schema.
   2. A database setup designed exclusively for backup and recovery.
   3. A database isolated for every single user in an organization.
   4. A database that stores data on multiple servers for one tenant only.

   Explanation: A multi-tenant database architecture means serving multiple clients or tenants from the same instance or schema, providing logical separation. The second option refers to sharding for one tenant, not multi-tenancy. The third describes single-tenant or dedicated databases, not multi-tenant. The last choice is about backup strategy, not about serving multiple tenants.

2. Shared Database, Shared Schema

   In the shared database and shared schema approach, how is tenant identification usually handled?

   1. By encrypting each tenant’s data differently.
   2. By creating a separate schema for each tenant.
   3. By deploying a dedicated server for each tenant.
   4. By including a tenant identifier column in every table.

   Explanation: The shared database, shared schema model uses a tenant identifier column in each table to distinguish data ownership. Separate schemas per tenant are part of the shared database, separate schema model. Deploying dedicated servers is a single-tenant strategy. Encrypting data differently per tenant may enhance security but is not how tenants are identified in this approach.

3. Data Isolation Levels

   Which multi-tenant database strategy provides the highest level of data isolation?

   1. Using one login credential for all tenants
   2. Dedicated database for each tenant
   3. Table partitioning for tenant data
   4. Shared schema for all tenants

   Explanation: Allocating a dedicated database per tenant ensures maximum data isolation, as each database is fully separated. Shared schemas combine tenant data, reducing isolation. Table partitioning separates data logically, not physically. A single login for all tenants does not address database separation or isolation.

4. Benefits of Shared Schema

   What is a primary advantage of using a shared schema design in a multi-tenant database?

   1. Automatic backup for each tenant without configuration
   2. Each tenant can use different database engines
   3. Simpler scaling and reduced maintenance overhead
   4. Guaranteed data isolation at the physical level

   Explanation: Shared schema designs allow for easy scaling and less maintenance since all tenants share structures and resources. Physical-level data isolation is less in this model. Allowing different database engines per tenant is not typically possible with shared schema. Backups still require specific configuration to ensure tenant data is preserved appropriately.

5. Schema-per-Tenant Approach

   In a database design where each tenant has a separate schema but shares the same database instance, what is this approach commonly called?

   1. Shared table, tenant view
   2. Shared schema, tenant field
   3. Shared database, separate schema
   4. Single-tenant dedicated instance

   Explanation: This approach is known as shared database, separate schema, where all tenants share the database instance but have individual schemas. Shared table with tenant view is not a standard term. Single-tenant dedicated instance refers to a one-to-one mapping per tenant. Shared schema, tenant field describes a shared schema with an identifying field, not separate schemas.

6. Performance Considerations

   Which scenario could lead to potential performance issues in a shared schema multi-tenant design?

   1. Each tenant’s data is stored in an isolated server with dedicated resources
   2. Each tenant has its own resource quota on separate servers
   3. One tenant generates an unusually high volume of queries affecting all tenants
   4. Tenants can only access their own schema

   Explanation: In a shared schema setup, resource spikes by a single tenant can cause contention and affect others because they share the same database resources. Quotas on separate servers offer true isolation. Storing data on isolated servers avoids inter-tenant resource conflicts. Restricting access to individual schemas is not relevant to shared schema designs.

7. Tenant Onboarding Complexity

   Which multi-tenant approach typically results in the fastest and simplest onboarding process for new tenants?

   1. Shared database, shared schema
   2. Separate database for each tenant
   3. Physical partitioning by tenant
   4. Single-tenant dedicated server

   Explanation: Shared database, shared schema allows rapid onboarding since tenants are added with minimal structural changes—mainly by assigning a new identifier. Single-tenant servers and separate databases require new instances or databases, increasing complexity. Physical partitioning is more advanced and typically slower to implement per tenant.

8. Schema Evolution Management

   What is a key challenge with schema-per-tenant multi-tenant database designs?

   1. Keeping schemas synchronized across all tenants during updates
   2. Allowing tenants to access each other’s data easily
   3. Supporting only text-based data fields
   4. Handling insufficient storage space in a shared environment

   Explanation: Schema-per-tenant approaches require careful management to update and synchronize schemas whenever database structure changes are needed. Lack of storage is not unique to this model. There's no restriction to text data only. Instead, tenant data separation is strong, so unauthorized data access is unlikely, not easier.

9. Security in Multi-Tenant Models

   In multi-tenant database systems, what is a common method to prevent tenants from accessing others’ data when using a shared schema?

   1. Creating a separate operating system account for every tenant
   2. Disabling user authentication altogether
   3. Implementing strict access controls and filtering by tenant identifier
   4. Allowing tenants to select their data by database password

   Explanation: Strict access controls and filtering queries using tenant identifiers ensures tenants access only their own data in shared schemas. Selection by database password is inadequate and not standard. Operating system accounts manage servers, not database-level logical security. Disabling user authentication would be highly insecure and unacceptable.

10. Cost Efficiency in Multi-Tenancy

    Why is the shared database, shared schema approach often considered more cost-efficient compared to isolated database models?

    1. It consolidates resources and reduces infrastructure duplication.
    2. It guarantees every query is encrypted with a different algorithm.
    3. It provides each tenant with unlimited server resources.
    4. It allows tenants to customize the database engine for their needs.

    Explanation: Shared database, shared schema models achieve cost efficiency by maximizing hardware and management resource sharing, minimizing duplication. Unlimited resource provision is unrealistic and not inherent to this approach. Engine customization is not supported in shared setups. While security is important, query encryption per tenant is not directly linked to cost efficiency.