Microsoft SQL Server
Microsoft SQL Server (Structured Query Language) is a proprietary relational database management system developed by Microsoft. As a database server, it is a software product with the primary function of storing and retrieving data as requested by other software applications—which may run either on the same computer or on another computer across a network (including the Internet).
History
The history of Microsoft SQL Server begins with the first Microsoft SQL Server product—SQL Server 1.0, a 16-bit server for the OS/2 operating system in 1989—and extends to the current day. Its name is entirely descriptive, it being server software that responds to queries in the SQL language.
Editions
Enterprise
SQL Server Enterprise Edition includes both the core database engine and add-on services, with a range of tools for creating and managing a SQL Server cluster. It can manage databases as large as 524 petabytes and address 12 terabytes of memory and supports 640 logical processors (CPU cores).
Standard
SQL Server Standard edition includes the core database engine, along with the stand-alone services. It differs from Enterprise edition in that it supports fewer active instances (number of nodes in a cluster) and does not include some high-availability functions such as hot-add memory (allowing memory to be added while the server is still running), and parallel indexes.
Web
SQL Server Web Edition is a low-TCO option for Web hosting.
Business intelligence
Introduced in SQL Server 2012 and focusing on Self Service and Corporate Business Intelligence. It includes the Standard Edition capabilities and Business Intelligence tools: Power Pivot, Power View, the BI Semantic Model, Master Data Services, Data Quality Services and x Velocity in-memory analytics.
Workgroup
SQL Server Workgroup Edition includes the core database functionality but does not include the additional services. Note that this edition has been retired in SQL Server 2012.
Express
SQL Server Express Edition is a scaled down, free edition of SQL Server, which includes the core database engine. While there are no limitations on the number of databases or users supported, it is limited to using one processor, 1 GB memory and 10 GB database files (4 GB database files prior to SQL Server Express 2008 R2). It is intended as a replacement for MSDE. Two additional editions provide a superset of features not in the original Express Edition. The first is SQL Server Express with Tools, which includes SQL Server Management Studio Basic. SQL Server Express with Advanced Services adds full-text search capability and reporting services.
Specialized Editions
Azure
Microsoft Azure SQL Database is the cloud-based version of Microsoft SQL Server, presented as a platform as a service offering on Microsoft Azure.
Azure MPP
Azure SQL Data Warehouse is the cloud-based version of Microsoft SQL Server in a MPP (massively parallel processing) architecture for analytics workloads, presented as a platform as a service offering on Microsoft Azure.
Scale limits
Feature | Enterprise | Standard | Web | Express with Advanced Services | Express |
Maximum compute capacity used by a single instance – SQL Server Database Engine | Operating system maximum | Limited to lesser of 4 sockets or 24 cores | Limited to lesser of 4 sockets or 16 cores | Limited to lesser of 1 socket or 4 cores | Limited to lesser of 1 socket or 4 cores |
Maximum compute capacity used by a single instance – Analysis Services or Reporting Services | Operating system maximum | Limited to lesser of 4 sockets or 24 cores | Limited to lesser of 4 sockets or 16 cores | Limited to lesser of 1 socket or 4 cores | Limited to lesser of 1 socket or 4 cores |
Maximum memory for buffer pool per instance of SQL Server Database Engine | Operating System Maximum | 128 GB | 64 GB | 1410 MB | 1410 MB |
Maximum memory for Column store segment cache per instance of SQL Server Database Engine | Unlimited memory | 32 GB | 16 GB | 352 MB | 352 MB |
Maximum memory-optimized data size per database in SQL Server Database Engine | Unlimited memory | 32 GB | 16 GB | 352 MB | 352 MB |
Maximum memory utilized per instance of Analysis Services | Operating System Maximum | 16 GB 64 GB | N/A | N/A | N/A |
Maximum memory utilized per instance of Reporting Services | Operating System Maximum | 64 GB | 64 GB | 4 GB | N/A |
Maximum relational database size | 524 PB | 524 PB | 524 PB | 10 GB | 10 GB |
Note:
Enterprise edition with Server + Client Access License (CAL) based licensing (not available for new agreements) is limited to a maximum of 20 cores per SQL Server instance. There are no limits under the Core-based Server Licensing model.
RDBMS high availability
Feature | Enterprise | Standard | Web | Express with Advanced Services | Express |
Server core support | Yes | Yes | Yes | Yes | Yes |
Log shipping | Yes | Yes | Yes | No | No |
Database mirroring | Yes | Yes | Yes | Yes | Yes |
Backup compression | Yes | Yes | No | No | No |
Database snapshot | Yes | Yes | Yes | Yes | Yes |
Always On failover cluster instances | Yes | Yes | No | No | No |
Always On availability groups | Yes | No | No | No | No |
Basic availability groups | No | Yes | No | No | No |
Automatic read write connection rerouting | Yes | No | No | No | No |
Online page and file restore | Yes | No | No | No | No |
Online index create and rebuild | Yes | No | No | No | No |
Resumable online index rebuilds | Yes | No | No | No | No |
Online schema change | Yes | No | No | No | No |
Fast recovery | Yes | No | No | No | No |
Accelerated database recovery | Yes | Yes | Yes | No | No |
Mirrored backups | Yes | No | No | No | No |
Hot add memory and CPU | Yes | No | No | No | No |
Database recovery advisor | Yes | Yes | Yes | Yes | Yes |
Encrypted backup | Yes | Yes | No | No | No |
Hybrid backup to Microsoft Azure (backup to URL) | Yes | Yes | Yes | No | No |
Cluster-less availability group | Yes | Yes | No | No | No |
Failover servers for disaster recovery | Yes | Yes | No | No | No |
Failover servers for high availability | Yes | Yes | No | No | No |
Failover servers for disaster recovery in Azure | Yes | Yes | No | No | No |
RDBMS security
Feature | Enterprise | Standard | Web | Express with Advanced Services | Express |
Row-level security | Yes | Yes | Yes | Yes | Yes |
Always Encrypted | Yes | Yes | Yes | Yes | Yes |
Always Encrypted with Secure Enclaves | Yes | Yes | Yes | Yes | Yes |
Dynamic data masking | Yes | Yes | Yes | Yes | Yes |
Server audit | Yes | Yes | Yes | Yes | Yes |
Database audit | Yes | Yes | Yes | Yes | Yes |
Transparent data encryption (TDE) | Yes | Yes | Yes | No | No |
Extensible key management (EKM) | Yes | Yes | No | No | No |
User-defined roles | Yes | Yes | Yes | Yes | Yes |
Contained databases | Yes | Yes | Yes | Yes | Yes |
Encryption for backups | Yes | Yes | No | No | No |
Data classification and auditing | Yes | Yes | Yes | Yes | Yes |