Difference between patch vs Hotfix vs Service pack

Difference between patch vs Hotfix vs Service pack
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Patch - Publicly released update to fix a known bug/issue

Hotfix - update to fix a very specific issue, not always publicly released

Service Pack - Large Update that fixes many outstanding issues, normally includes all Patches, Hotfixes, Maintenance releases that predate the service pack

Types of Pages in SQL Server

Types of Pages in SQL Server

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• Data Page: It holds the data entered by the user but not the data which is of type text, ntext, nvarchar(max), varchar(max), varbinary(max), image and xml data.
• Index: It stores the index entries.
• Text/Image: It stores LOB ( Large Object data) like text, ntext, varchar(max), nvarchar(max),  varbinary(max), image and xml data.
• GAM & SGAM ;They are used for saving information related to the allocation of extents.
• PFS (Page Free Space): Information related to page allocation and unused space available on pages.
• IAM (Index Allocation Map): Information pertaining to extents that are used by a table or index per allocation unit.
• BCM (Bulk Changed Map): Keeps information about the extents changed in a Bulk Operation.
• DCM (Differential Change Map): This is the information of extents that have modified after the last Full BACKUP statement as per allocation unit.

EDITIONS OF SQL SERVER

EDITIONS OF SQL SERVER:-

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SQL Server 2012 Standard Edition

·         Limited to 16 Cores & 64GB of RAM

·         It includes support for two-node Always On Failover Clusters, and it’s licensed either per core or per server.

SQL Server 2012 Business Edition

·         SQL Server 2012 Business Intelligence Edition is a new member of the SQL Server family.

·         Limited to 16 cores &  64GB of RAM for db engine. However, it can use the maximum number of cores supported by the OS for Analysis Services and Reporting Services because this is BI Edition.

·         This Edition includes all of the features in the Standard edition and support for advanced BI features, but it lacks support for the advanced availability features like AlwaysOn Availability Groups and other online operations. The BI Edition supports two-node AlwaysOn Failover Clusters, and it’s licensed per server.

SQL Server 2012 Enterprise Edition

·         SQL Server 2012 Enterprise Edition has everything that SQL Server offers.

·         It supports the maximum number of cores and RAM in the host OS and provides the complete SQL Server feature set, including support for all of the advanced availability and BI features.

·         The Enterprise edition supports up to 16-node AlwaysOn Failover Clusters & AlwaysOn AG.

·         The Enterprise edition is licensed per core.

SQL Server 2012 Express Editions

SQL Server 2012 offers free edition as SQL Server Express Edition and The Express editions are limited to support for one CPU and 1GB of RAM. Databases are limited to 10GB per database.

SQL Server 2012 Web and Developer Editions.SQL Server 2012 Web Edition and SQL Server 2012 Developer Edition are same as previous versions. The Developer edition provides the same feature set as the Enterprise edition. However, it’s licensed per developer and can’t be used for production work. The Web edition is licensed only to hosting companies with a Services Provider License Agreement (SLPA).