First published on MSDN on Apr 26, 2018
Azure SQL database is a platform as a service SQL Server Database Engine hosted in Azure cloud and managed by Azure. Azure automates many management activities and enables you to focus on development and optimizations. In addition, it enables you to easily configure some advanced management configurations.
There are some critical database management activities that you need to do in order to ensure that your database is running without any issues:
Azure SQL database has many of these activities built-in and automated. You can leverage existing mechanism and more easily managed your database.
Having the backups for your database is crucial for your management operations. Backups ensure that you can easily recover if any error happens, some data is accidentally deleted, or if some wrong data is entered in your database.
Azure SQL Database manages backups for you and automatically creates backups of your databases. Full database backups happen weekly, differential database backups generally happen every few hours, and transaction log backups generally happen every 5 - 10 minutes. Backups are kept 7 days in Basic tier, and 35 days in Standard/Premium tiers. New General Purpose/Business Critical tiers have configurable backup retention with 35 days maximum backup retention period, and default value 7 days. Backups are retained even if you delete a database, which allows you to restore accidentally deleted databases. You can also keep
database backups for up to 10 years
Backups allow you to restore a database to a specific
to the same server that hosts the database. When you restore a database, the service figures out which full, differential, and transaction log backups need to be restored. You can restore a database on a server in different Azure region from the most recent geo-replicated full and differential backups. Geo-restore uses a geo-redundant backup as its source and can be used to recover a database even if the database or datacenter is inaccessible due to an outage.
Backups are encrypted
if Transparent Data Encryption is enabled in your database (which is the default setting for new database).
Azure SQL database has built-in High availability mechanism that guarantees 99.99% of availability of your databases and you don’t need to configure anything. You have some additional options that you can configure in order to establish additional availability:
: SQL Database allows you to configure up to four readable secondary databases in either the same or globally distributed Azure data centers. For example, if you have a SaaS application with a catalog database that has a high volume of concurrent read-only transactions, use active geo-replication to enable global read scale and remove bottlenecks on the primary that are due to read workloads. Active geo-replication allows for the failover of a single database.
: SQL Database allows you to enable high availability and load balancing at global scale, including transparent geo-replication and failover of large sets of databases and elastic pools. Failover groups and active geo-replication enables creation of globally distributed SaaS applications with minimal administration overhead leaving all the complex monitoring, routing, and failover orchestration to SQL Database. Failover groups allows for the failover of multiple databases within a single group.
: SQL Database allows you to provision Premium or Business Critical (preview) databases or elastic pools across multiple availability zones. Because these databases and elastic pools have multiple redundant replicas for high availability, placing these replicas into multiple availability zones provides higher resilience, including the ability to recover automatically from the datacenter scale failures without data loss. This feature is currently in preview.
Azure SQL Database has built-in intelligence that constantly monitors the activities in your database and takes corrective actions if the issue might be mitigated. There are two
features that can improve your database performance:
Automatic indexing that analyzes your T-SQL queries identifies the indexes that could be added into the database, apply indexes, and measures workload performance in order to prove that the new index improved performance. If the index didn’t improved performance, it would be dropped.
Automatic plan correction monitors performance of you query plans and automatically applies some previous good plan if the current plan degrades performances.
Azure SQL Database might automatically apply Automatic tuning corrective actions, or you can keep them in the "advisor mode" where Azure SQL database would just report recommendations and let you review them and apply the ones that you find most useful.
In addition there are many internal built-in Database Engine optimization techniques that enable Database engine to learn from your workload and dynamically adapt query plans.
Azure SQL Database exposes information about the activities that are happening in your database. In addition, it processes information emitted from database and tries to identify problems and to give you more details about the potential solutions. You have the following features that can help you to monitor your database:
SQL Database Auditing
tracks database events and writes them to an audit log in your Azure storage account. Auditing can help you maintain regulatory compliance, understand database activity, and gain insight into discrepancies and anomalies that could indicate business concerns or suspected security violations.
is a set of views in Database Engine that enables you to track performance of your database queries and identify performance issues.
analyze events related to performance of your queries and give you the root causes of the identified problems.
constantly monitors queries and notifies you if some potential threat is identified (for example SQL Injection attempt)
Transparent data encryption
transparently encrypts data stored in data/log/backup files, ensuring that nobody can take and read the data stored on disks.
enables you to keep sensitive columns encrypted and to decrypt their values on the client side. Nobody can read sensitive information in database, unless if it has the matching certificate on the client side.
These security policies might help you to keep your data secured and more easily certify your solution from the security perspective.
Azure SQL Database is pre-configured SQL Server Database Engine hosted in Azure cloud that has built-in different management capabilities. In most of the cases you can use default management setting and let Azure manage your database. However, if you need to do some additional management actions or configurations, Azure SQL Database might make your tasks easier.