MS Azure : SQL Database Service Pricing Tier Part - 1

SQL Database Service Pricing Tier

On the top layer Database pricing is classified in two models:

A. Single Database

Single databases are fully isolated databases optimized for workloads when performance demands are somewhat predictable. You can scale a single database up or down through the Basic, Standard and Premium service tiers to get the performance and features your app needs, precisely when it needs them. Each tier is distinguished primarily by performance, which is measured in Database Transaction Units (DTUs).

B. Elastic Pool

Elastic pools let you manage the collective performance of a pool of databases rather than single databases. The databases in the pool automatically scale up and down to meet demand. You can easily add and remove databases from the pool, scaling your app from a handful of databases to thousands, all within a budget you control.

In the first release of the SQL Database service pricing tier, there were two type of configuration:
1. Web DB - Web Database is basically for web sites and web apps, its limited up to 5GB.
2. Business DB - Business database is basically for data-warehouse and for big project, its limited up to 150 GB.

In the current configuration of the SQL Database Service pricing tier are distinguished in three categories:
1. Basic
2. Standard
3. Premium

These tiers distinguished based on following characteristics:
1. Size : Size limit of the database.
2. Performance : Performance of the database which is measured in DTUs ( Database Transaction Units ).
3. Concurrency : Concurrency related to login attemps, sessions and work threads, we will discuss more about this.
4. Recovery : Recovery is directly related to Point in Time Restore, which is different for each category of pricing tier.
5. Features : There are few advance features which are only available in high tiers like In-memory OLTP, Column-store Indexes.

Now Lets discuss the Current Categories of SQL Database Service pricing tier for Single Database model, which is most commonly used in comparison to Elastic Pool Model.

A. Single Database

1. Basic : There is only 1 type, which is known as B.
Size Limit : 2 GB Max storage per DB
Performance : 5 DTUs
Recovery : Point in Time Restore 7 Days.
Features : Doesn't Supports In-memory OLTP and Column-store Indexes

2. Standard : Standard is further distinguished in 4 type as follows:
Size Limit : 250 GB Max storage per DB
Performance : 10-100 DTUs
Recovery : Point in Time Restore 35 Days.
Features : Doesn't Supports In-memory OLTP and Column-store Indexes

3. Premium : Premium is further distinguished in 6 type as follows:
Size Limit : 500-1024 GB Max storage per DB
Performance : 125-4000 DTUs
Recovery : Point in Time Restore 35 Days.
Features : Supports In-memory OLTP and Column-store Indexes

Concurrency : Concurrency is based on Login Attempts, Worker Threads and Sessions per database details are different for each Tier:

Click here for Elastic Pool

Click Here , For more details and exact pricing.

MS Azure : What is Azure Database?

MS Azure Database : Cloud Database as a Service
- Azure SQL Database is a Database as a service offering on Microsoft Azure.
- It aims to reduce the cost of running database infrastructure.
- The service is billed by the hour, based on the service tier of the database.
- The service is easily provisioned through different methods.

What is Database as a Service (DaaS)?
Daas is a public cloud offering defined by 3 fundamental characteristics.
1. The Service provider owns and manage the database software, admin task like backup/restore and high availability, the operating system and hardware.
2. The service users pay according to their usage of the service. There is no upfront expense or contract lock-in unless the user wants it.
3. Users can scale up or down on demand and also create and destroy environments on demand with no provider intervention.

Billing Model
1. The Service is paid by the hour.
2. The hourly rate is based on the highest service tier selected during that hour.

As a DBA, What is your responsibility?
When SQL Database on VM:
1. Maintain the Operating System.
2. Maintain SQL Server Services and its Databases.
3. Setup Backups
4. High Availability
5. Disaster Recovery
6. Change Control, performing changes on production with minimal downtime.
7. Performance, have to ensure database is providing good performance
8. Security, database should be secure.

When SQL Database on MS Azure:
1. Choosing the right service tier.
2. Test the High Availability and Disaster Recovery Strategy.
3. Change Control, performing changes on production with minimal downtime.
4. Performance, have to ensure database is providing good performance
5. Security, database should be secure.

Advantages of MS Azure SQL Database
1. Pay for what you use by the hour.
2. No need to maintain hardware, virtualization, Operating System Or database software.
3. Scale Up Or Down the resources on Demand.