Exam AZ-305 topic 4 question 52 discussion

There are *16* variations of this question. Each of them offering different possible answers. The answer priority is as follows. If it exists then choose it. If it doesn't, proceeded to the next priority. Sometimes both appear in the same question, so make sure to select the higher priority. 1. Azure SQL Database Premium 2. Azure SQL Database Serverless 3. Azure SQL Database Business Critical

The given answer is correct

Supports availability Zones, Synchronous replication and built-in HA and minimizes costs.

D. Azure SQL Database Serverless Cost-effective ✅ No high availability with synchronous replication ❌ No zone redundancy ❌ ❌ Not suitable for zero data loss or zone outages.

Correct answer is - Azure SQL Database Business Critical Why? Azure SQL Database Serverless – Does not support zone-redundant deployment and is not designed for high availability with fast failover. Azure SQL Managed Instance Business Critical – Provides HA but is more expensive than a single Azure SQL Database in Business Critical Azure SQL Managed Instance General Purpose – Uses remote storage, so failover may result in data loss and does not offer built-in zone redundancy

If this is a hard requirement, there are ONLY two options:Failover between replicas of the database must occur without any data loss. -> Azure SQL Managed Instance Business Critical and Azure SQL Database Business Critical (which cheaper). Why?: Because these are the only one with sync. replication. All others are asyc.

Azure SQL Database Serverless: Suitable for intermittent workloads. Does not offer zone redundancy or Business Critical features.

Synchronous Replication is required for guarranteed Zero Data loss during failover, below 3 model supports it, others do asynchronous so there is a chance of data loss. Ordered in terms of cost, 3 being most expensive 1. Azure SQL Database Business Critical 2. Azure SQL Database Premium 3. Azure SQL Managed Instance - Business Critical

because you need no data loss

Azure SQL Database Business Critical

I believe the correct answer is C. Serverless is available in vCore General Purpose and Hyperscale but both of them are not Always ON architecture. Business Critical in vCore and Premium in DTU use Always ON and no data loss. https://learn.microsoft.com/en-us/azure/azure-sql/database/high-availability-sla?view=azuresql&tabs=azure-powershell

Azure SQL Business Critical is the right answer imho. Serverless is cheap but does not guarantee failover without data loss

Azure SQL Database Business Critical is indeed more expensive compared to Azure SQL Database Serverless, but it provides the high availability and resilience required in the scenario. Azure SQL Database Serverless can be more cost-effective, particularly for infrequent, intermittent, or unpredictable workloads, because you pay for compute resources only when the database is active. However, it doesn't inherently guarantee the same level of high availability, resilience, and automatic failover without data loss across zones as the Business Critical tier. Azure SQL Database Business Critical best meets all the requirements, even though it may not be the most cost-effective option. If cost is a primary concern and the high availability requirements can be slightly relaxed, Azure SQL Database Serverless could be considered. However, based on the requirements stated, Business Critical is the recommended choice.

Failover without data loss: Azure SQL Database Serverless does not provide the same level of high availability as Azure SQL Database Business Critical. With Serverless, automatic failover is not guaranteed, and there may be a risk of data loss during failover. Availability in the event of a zone outage: Azure SQL Database Serverless does not support the ability to span multiple availability zones. In the event of a zone outage, there is a possibility of downtime or unavailability of the database. Cost optimization: Azure SQL Database Serverless offers cost optimization benefits as it automatically pauses and scales based on usage. It is a suitable option for databases with unpredictable or intermittent workloads. However, cost optimization should not be the sole factor in choosing a deployment option if meeting high availability and data integrity requirements is crucial.

It should be C, this is an important concept for understanding business continuity from the perspective of Azure SQL. "The Basic, Standard, and General Purpose service tiers use the remote storage availability model for both serverless and provisioned compute." Meaning if the remote storage is down then there will be loss of data before you can provision/attach new storage. Hence it has to be business critical, reference link given below. https://learn.microsoft.com/en-us/azure/azure-sql/database/high-availability-sla?view=azuresql&tabs=azure-powershell#:~:text=The%20Basic%2C%20Standard%2C%20and%20General%20Purpose%20service%20tiers%20use%20the%20remote%20storage%20availability%20model%20for%20both%20serverless%20and%20provisioned%20compute

i think should be C, when talking about zero data loss during failover, shouldn't we use premium tier ? i've checked from the portal , cost from lowest to highest is SQL Preium < SQL BC < SQL MI BC.

Azure SQL Database Business Critical provides high availability with the capability to automatically replicate data to a secondary replica within the same region, ensuring zero data loss in the event of a failover. The deployment option also provides cross-region replication to ensure availability in case of a zone outage. Azure SQL Managed Instance Business Critical also provides high availability, but it is more expensive than Azure SQL Database Business Critical. Azure SQL Managed Instance General Purpose and Azure SQL Database Serverless do not provide the required level of high availability for this scenario. Therefore, Azure SQL Database Business Critical meets all the requirements while keeping costs minimized.