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

FeatureEnterpriseStandardWebExpress
with
Advanced
Services
Express
Maximum compute capacity used by a single instance – SQL Server Database Engine Operating system maximumLimited to lesser of 4 sockets or 24 coresLimited to lesser of 4 sockets or 16 coresLimited to lesser of 1 socket or 4 coresLimited to lesser of 1 socket or 4 cores
Maximum compute capacity used by a single instance – Analysis Services or Reporting ServicesOperating system maximumLimited to lesser of 4 sockets or 24 coresLimited to lesser of 4 sockets or 16 coresLimited to lesser of 1 socket or 4 coresLimited to lesser of 1 socket or 4 cores
Maximum memory for buffer pool per instance of SQL Server Database EngineOperating System Maximum128 GB64 GB1410 MB1410 MB
Maximum memory for Column store segment cache per instance of SQL Server Database EngineUnlimited memory32 GB16 GB352 MB352 MB
Maximum memory-optimized data size per database in SQL Server Database EngineUnlimited memory32 GB16 GB352 MB352 MB
Maximum memory utilized per instance of Analysis ServicesOperating System Maximum16 GB 

64 GB
N/AN/AN/A
Maximum memory utilized per instance of Reporting ServicesOperating System Maximum64 GB64 GB4 GBN/A
Maximum relational database size524 PB524 PB524 PB10 GB10 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 

FeatureEnterpriseStandardWebExpress
with
Advanced
Services
Express
Server core support YesYesYesYesYes
Log shippingYesYesYesNoNo
Database mirroringYesYes Yes Yes Yes 
Backup compressionYesYesNoNoNo
Database snapshotYesYesYesYesYes
Always On failover cluster instances YesYesNoNoNo
Always On availability groups YesNoNoNoNo
Basic availability groups NoYesNoNoNo
Automatic read write connection reroutingYesNoNoNoNo
Online page and file restoreYesNoNoNoNo
Online index create and rebuildYesNoNoNoNo
Resumable online index rebuildsYesNoNoNoNo
Online schema changeYesNoNoNoNo
Fast recoveryYesNoNoNoNo
Accelerated database recoveryYesYesYesNoNo
Mirrored backupsYesNoNoNoNo
Hot add memory and CPUYesNoNoNoNo
Database recovery advisorYesYesYesYesYes
Encrypted backupYesYesNoNoNo
Hybrid backup to Microsoft Azure (backup to URL)YesYesYesNoNo
Cluster-less availability group YesYesNoNoNo
Failover servers for disaster recovery YesYesNoNoNo
Failover servers for high availability YesYesNoNoNo
Failover servers for disaster recovery in Azure YesYesNoNoNo

RDBMS security

FeatureEnterpriseStandardWebExpress
with
Advanced
Services
Express
Row-level securityYesYesYesYesYes
Always EncryptedYesYesYesYesYes
Always Encrypted with Secure EnclavesYesYesYesYesYes
Dynamic data maskingYesYesYesYesYes
Server auditYesYesYesYesYes
Database auditYesYesYesYesYes
Transparent data encryption (TDE)YesYesYesNoNo
Extensible key management (EKM)YesYesNoNoNo
User-defined rolesYesYesYesYesYes
Contained databasesYesYesYesYesYes
Encryption for backupsYesYesNoNoNo
Data classification and auditingYesYesYesYesYes