SQL Server SPs, CUs and hotfixes for SAP

The first cumulative update package (CU1) of SQL Server 2008 was released last week. You can download it from https://support.microsoft.com/kb/956717/en-us. SAP will not support SQL 2008 RTM – at least CU1 has to be installed. [April 2009: in the meanwhile CU2 is the minimum supported version by SAP] The SQL Server DVD from SAP will include an unattended installation, which installs SQL Server 2008 and CU1 consecutively.

Which SP, CU or hotfix is supported by SAP?
In the past there was some confusion about the SQL Server versions required for SAP. As a basic principle SAP tests, supports and delivers each SQL Server Service Pack. Once a new Service Pack is released we encourage SAP customers to apply it. If an important fix is generally needed for SAP databases then we state the build number of the fix as the minimum SQL Server build required for SAP. This is typically the build number of the actual Service Pack, but it also could be a cumulative update or hotfix. SAP note #62988 describes in detail the actual SQL Server versions supported by SAP. Currently you need at least build 9.00.3042 for SQL Server 2005 and build 8.00.2039 for SQL Server 2000. SQL Server 2008 is not mentioned in the note yet because it is still in SAP’s final software validation stage.
We do not encourage SAP customers to apply each and every cumulative update or hotfix once it is available from Microsoft. The fact that a hotfix is not listed in OSS note #62988 does not mean that this fix can’t be used in an SAP system. If a hotfix is recommended by Microsoft support to solve a particular problem at a customer’s system, then SAP will support this hotfix, even if it is not mentioned in SAP note #62988.

What’s special for fixes of SQL Native Client?
An issue of SQL Server Native Client (SNAC) does not only concern the database server. A hotfix of SNAC has to be installed on each and every SAP application server. This can be easily missed, in particular in large data centers with dedicated Windows, database and SAP administrators. When installing a new SAP application server you should therefore double check that you have installed the same SNAC version as on the database server. SAP also checks this and displays any mismatch in transaction RZ20. The most severe SNAC issue is described in SAP note #1067103. SAP implemented a workaround in the SAP database interface (DBSL, dbmssslib.dll). The DBSL will automatically be replicated to each SAP application server once an SAP NetWeaver ABAP instance starts up. Therefore this particular issue will not occur for ABAP even if the necessary SNAC fix was not applied to all application servers.

What’s special for the installation of SQL Server for an SAP system?
SAP as a reseller of SQL Server delivers its own SQL Server DVD. This DVD contains exactly the same bits as the retail version of SQL Server. In order to simplify the SQL Server (2000, 2005 and 2008) installation for SAP, a VB-script is delivered by SAP as well. Double-clicking SQL4SAP.VBS starts the customized installation of SQL Server for SAP. It is not mandatory to install SQL Server via the SAP delivered VB-script. The manual installation and required settings are described in the SAP installation guide as well. The customer has the choice which way to install.

SQL4SAP does install unattended with the correct configuration for SAP and hence avoids mistakes in manual installations. It installs SQL Server Enterprise Edition, the latest service pack and cumulative update consecutively. The script performs comprehensive prerequisite tests and automatically chooses the right platform (x86, x64, IA64). SQL4SAP always installs the collation SQL_Latin1_General_CP850_BIN2, which is mandatory for an SAP system. It enables TCP/IP, Named Pipes and Shared Memory and sets some configuration options to 1 ('show advanced options', 'max degree of parallelism', 'xp_cmdshell'). For security reasons, the SQL Server authentication mode is set to “Windows Only”. In addition the SQL login “sa” has a random password and is disabled. For further details about the customized installation of SQL Server for SAP read the attached SAP guide.

SQL4SAP_docu.pdf