Sql Server Blog di Francesco Diaz : Sql Server 2005

Restituire l’ SPID della sessione DAC attiva

Francesco Diaz — Tue, 15 Sep 2009 19:19:54 GMT

E’ possibile eseguire la semplice query seguente per recuperare l’informazione.

SELECT S.session_id
FROM sys.tcp_endpoints E JOIN sys.dm_exec_sessions S
ON E.endpoint_id = S.endpoint_id
WHERE E.name = 'Dedicated Admin Connection'

Ricordo che su Sql Server Express Edition è necessario avviare l’istanza con il trace flag 7806 per rendere possibile l’uso delle sessioni DAC.

Recuperare la definizione di un oggetto di sistema

Francesco Diaz — Wed, 05 Aug 2009 16:44:06 GMT

Ci sono diversi metodi per farlo, come utilizzare la stored procedure sp_helptext, fare una query sulla vista sys.system_sql_modules o una chiamata alla funzione object_definition.

Di seguito un esempio con sys.tables :

-- SP_HELPTEXT

sp_helptext 'sys.tables'

-- OBJECT_DEFINITION

SELECT OBJECT_DEFINITION (object_id('sys.tables'))

-- SYS.SYSTEM_SQL_MODULES (recupero schema_id e object_id dell’oggetto)

SELECT schema_id FROM sys.schemas WHERE name = 'sys'
SELECT object_id FROM sys.system_views WHERE name = 'tables' AND schema_id = 4
SELECT [definition] FROM sys.system_sql_modules WHERE object_id = -386

Come individuare gli utenti orfani in un database

Francesco Diaz — Thu, 30 Jul 2009 18:03:53 GMT

Per individuare gli utenti orfani (senza un login associato) di un database è possibile utilizzare la stored procedure sp_change_user_login utilizzando il parametro @action ed impostandolo su Report. Di seguito un esempio del database AdventureWorks che ha l’utente Customer3 che non è associato a nessun login sull’istanza:

Per mappare un utente del database ad una login è invece meglio utilizzare l’istruzione T-SQL ALTER USER .

Rinominare un server che esegue Sql Server

Francesco Diaz — Thu, 16 Jul 2009 10:26:19 GMT

Ho raccolto in questo post i documenti utili nel caso sia necessario rinominare un server standalone che esegue Sql Server o un Virtual Server in caso di configurazioni in Failover Cluster.

NOTA : Sql Server 2000 non supporta questa operazione per i virtual server clustered.

Sql Server 2008 standalone

http://msdn.microsoft.com/en-us/library/ms143799.aspx

Considerazioni :

SQL Server does not support renaming computers that are involved in replication, except when you use log shipping with replication. The secondary computer in log shipping can be renamed if the primary computer is permanently lost. For more information, see Replication and Log Shipping.
When you rename a computer that is configured to use Reporting Services, Reporting Services might not be available after the computer name change. For more information, see Renaming a Report Server Computer.
When you rename a computer that is configured to use database mirroring, you must turn off database mirroring before the renaming operation. Then, re-establish database mirroring with the new computer name. Metadata for database mirroring will not be updated automatically to reflect the new computer name. Use the following steps to update system metadata.
Users who connect to SQL Server through a Windows group that uses a hard-coded reference to the computer name might not be able to connect to SQL Server. This can occur after the rename if the Windows group specifies the old computer name. To ensure that such Windows groups have SQL Server connectivity following the renaming operation, update the Windows group to specify the new computer name.

Sql Server 2008 cluster

http://msdn.microsoft.com/en-us/library/ms178083.aspx

Considerazioni :

SQL Server does not support renaming servers involved in replication, except in the case of using log shipping with replication. The secondary server in log shipping can be renamed if the primary server is permanently lost. For more information, see Replication and Log Shipping.
When renaming a virtual server that is configured to use database mirroring, you must turn off database mirroring before the renaming operation, and then re-establish database mirroring with the new virtual server name. Metadata for database mirroring will not be updated automatically to reflect the new virtual server name.

Sql Server 2005 standalone

http://msdn.microsoft.com/en-us/library/ms143799(SQL.90).aspx

Sql Server 2005 cluster

http://msdn.microsoft.com/en-us/library/ms178083(SQL.90).aspx

Sql Server 2000 standalone

http://msdn.microsoft.com/en-us/library/aa197071(SQL.80).aspx

Sql Server 2000 cluster

http://support.microsoft.com/kb/307336/en-us

renaming the SQL Server virtual, or clustered, servers is not supported in the current version of Microsoft SQL Server. If you rename the SQL Server Network Name resource, a variety of problems may occur

System Center Data Protection Manager 2007 : proteggere SQL

Francesco Diaz — Thu, 18 Jun 2009 12:50:06 GMT

Vi segnalo un Virtual Lab di 90 min. sulla protezione di Sql Server con System Center Data Protection Manager 2007 :

http://msevents.microsoft.com/CUI/WebCastEventDetails.aspx?EventID=1032407492&EventCategory=3&culture=en-US&CountryCode=US

Vi ricordo anche alcune delle principali caratteristiche di DPM 2007 applicate a Sql Server :

Enhanced SQL Server 2008 protection, including the addition of new protection capabilities for mirrored databases, support for parallel backups of databases within a single instance, and the ability to move data from SQL Server 2005 to SQL Server 2008 for migration scenarios.
DPM 2007 offers integrated support for advanced Exchange and SQL cluster configurations, shorter SQL backup windows with out the need for compression, as well as advanced SharePoint data protection options.
DPM 2007 enables lossless recovery of Exchange, SQL, and SharePoint servers without the need for constant replication or synchronization by seamlessly integrating a point in time database restore with the existing application logs.
When protecting SQL Servers with “Log Shipping” or “Simple Recovery Model” configurations, DPM auto-configures itself to co‑exist for simple-mode protection where needed.

Per ulteriori informazioni vi rimando ai seguenti riferimenti :

Sito web del prodotto : http://www.microsoft.com/systemcenter/dataprotectionmanager/en/us/product-details.aspx

Un white paper sulla protezione di Sql Server con DPM 2007 : http://download.microsoft.com/download/1/5/3/15343F57-36F4-44A0-B3F7-759812166644/DPM2007sp1_whitepaper_Protecting_SQL_Server_with_DPM2007.pdf

Scalable Shared Database

Francesco Diaz — Mon, 25 May 2009 18:36:32 GMT

Gli scalable shared databases consentono di effettuare la scalabilità orizzontale di un database in sola lettura da utilizzare per scopi di reportistica.

Scenario

La procedura di configurazione può essere divisa in due macro categorie:

La fase di creazione, che rappresenta il momento in cui il database dei report viene preparato
La fase di collegamento, che comporta l’aggancio dei volumi della SAN che contengono il database condiviso ai server di reportistica.

Vantaggi

Scalabilità orizzontale
Isolamento del carico di lavoro perchè ogni server di reportistica usa le proprie risorse e il proprio tempdb
Stessi dati su tutti i server

Aggiornamento di un database condiviso

L’update-cycle di un database condiviso è diviso in tre fasi :

La fase di detach del database da ognuno dei server di reportistica
La fase di refresh dei dati
La fase di attach del database aggiornato ai vari server.

Informazioni utili

Informazioni generali, caratteristiche e limitazioni : http://technet.microsoft.com/en-us/library/ms345392.aspx

Come migliorare la disponibilità di uno scalable shared database : http://technet.microsoft.com/en-us/library/ms345596.aspx

Come creare e aggiornare il database di reportistica : http://technet.microsoft.com/en-us/library/ms345390.aspx

La fase di detach e attach del database.

Aggiornamento policy di supporto di Sql Server in ambiente virtualizzato – KB 956893

Francesco Diaz — Tue, 19 May 2009 12:13:21 GMT

Il documento 956893 contiene un importante aggiornamento, Sql Server (2005/2008) è ora supportato in configurazioni di Guest Failover Cluster in ambiente virtualizzato. Alcuni dettagli :

Guest Failover Clustering is supported for SQL Server 2005 and SQL Server 2008 in a virtual machine for Windows Server 2008 with Hyper-V, Microsoft Hyper-V Server 2008, and SVVP certified configurations provided both of the following requirements are met:

The Operating System running in the virtual machine (the “Guest Operating System”) is Windows Server 2008 or higher
The virtualization environment meets the requirements of Windows 2008 Failover Clustering as documented at The Microsoft Support Policy for Windows Server 2008 Failover Clusters.
Guest Failover Clustering is when you create a SQL Server failover cluster inside a virtual machine where the nodes are running as a virtual machine. A non-SVVP configuration that meets these requirements will receive support from Microsoft CSS per the policies documented in
897615 (http://support.microsoft.com/kb/897615/ ) Support policy for Microsoft software running in non-Microsoft hardware virtualization software

The virtual machine must be running an operating system that is supported for the specific SQL Server version and edition and that is supported for virtualization.

The SQL Server product must be a supported version under its current Microsoft Support Lifecycle policy. For more information about Microsoft Support Lifecycle policies, visit the following Microsoft Support Web site:

Posso configurare il Database mirroring con … - Parte 4

Francesco Diaz — Sun, 19 Apr 2009 19:36:14 GMT

Le repliche. Si, ma con alcune considerazioni da fare.

Il failover dal principal al mirror è supportato solo per il database di pubblicazione, non per quelli di distribuzione e sottoscrizione.
Il principal ed il mirror devono condividere il server di distribuzione, possibilmente su un server remoto.
Il database di pubblicazione per una replica Merge o Transazionale va bene per sottoscrizioni in sola lettura o per aggiornamenti tramite code, non per aggiornamenti immediati tramite MSDTC, non per server di pubblicazione in topologia peer-to peer e republish, non per server di pubblicazione Oracle.

Riferimenti utili

Architettura logica delle repliche : http://msdn.microsoft.com/en-us/library/bb500355.aspx

Architettura fisica delle repliche : http://msdn.microsoft.com/en-us/library/bb500345.aspx

Quale tipologia di replica è meglio scegliere a seconda dello scenario : http://msdn.microsoft.com/en-us/library/ms152565.aspx

Sql Server Database Engine Tuning Advisor : funzionalità non supportate

Francesco Diaz — Wed, 08 Apr 2009 14:23:40 GMT

Il Database Engine Tuning Advisor può essere utilizzato per ottimizzare i database di Sql Server. Non tutte le funzionalità sono però supportate a seconda della versione di Sql utilizzata. Di seguito trovate la tabella e il link al documento che ne descrive i dettagli.

Tuning Options Not Supported by Database Engine Tuning Advisor

The following table lists the unsupported options in detail for Database Engine Tuning Advisor.

Option	SQL Server 2008 Standard edition	SQL Server 2005 and SQL Server 2000 Standard editions	SQL Server 2000 Enterprise, Developer, and Enterprise Evaluation editions
Indexes and indexed views 1	Not supported	Not supported	Supported
Indexed views 1	Not supported	Not supported	Supported
Include filtered indexes 2	Supported	Not supported	Not supported
Full partitioning	Not supported	Not supported	Not supported
Aligned partitioning	Not supported	Not supported	Not supported
Keep aligned partitioning	Not supported	Not supported	Not supported
Generate online recommendations where possible	Not supported	Not supported	Not supported
Generate only online recommendations	Not supported	Not supported	Not supported

1 These options are disabled in the user interface.

2 Filtered indexes are not supported on any edition before SQL Server 2008.

Riferimenti utili:

http://msdn.microsoft.com/en-us/library/ms345360.aspx

In-Place vs Side-by-Side upgrade

Francesco Diaz — Tue, 16 Dec 2008 21:31:48 GMT

La decisione di migrare a Sql Server 2008 da una versione precedente (2000, 2005) comporta una prima scelta fondamentale : Upgrade in-place (l'istanza viene aggiornata a Sql Server 2008) o side-by-side (viene creata una nuova istanza sullo stesso server o su un server differente e poi gli oggetti vengono copiati manualmente nella nuova istanza). Nella tabella seguente trovate la lista dei vantaggi di entrambe le scelte e in fondo al post il link al documento che oltre alla tabella contiene tutte le informazioni necessarie di cui tenere conto per l'upgrade. Insieme al Books on line costituisce una risorsa fondamentale da tenere in considerazione se vi trovate in fase di pianificazione di un upgrade.

Consideration	In-Place Upgrade Advantages	Side-by-Side Upgrade Advantages
Require the fewest hours for the upgrade deployment team to plan and prepare the upgrade effort	· Setup automatically upgrades data and settings in place, without the need for a manual transfer of data or settings. · The resulting upgraded instance has the same name as the original. · Applications continue to connect to the same instance name.	· It gives more granular control over which database objects are migrated. · The legacy database server can run alongside the new server. You can perform test migrations and research and resolve compatibility issues without disturbing the production system. · The legacy database server remains available during the migration, although it cannot be updated for at least the time that is required to transfer data. · Applications can be moved from legacy system in a staged manner instead of all at the same time. Even though your system might have passed all validation and acceptance test, a problem could still occur (see Murphy’s Law). If a problem does occur, then you will be able to roll back to the legacy system.
Require minimal DBA skill set expertise (or no DBA available to implement the upgrade)	A junior DBA or System Engineer or similar with basic knowledge and adherence to good IT practices can complete upgrades without special scripts or manual interventions; Setup automates the upgrade process.	System recovery: If a junior DBA or anybody who is not familiar with the upgrade process has any problems, the production environment remains untouched. Only when the new system is approved by Test / QA will the users be migrated to the new server.
Require minimal user downtime	For small data sets, the total end-to-end time might be smaller because this is the most automated upgrade strategy.	By controlling the steps directly, you can do much of the preparation including much of the data transfer can be completed without user downtime; some user downtime is still required to update the instance version.
Require fastest possible revert/rollback in case issue encountered		The legacy instance of SQL Server is still present at the end of the upgrade and may be used as a rollback option.
Schedule different downtime windows for different user databases within the same instance		Can separately control when each user database is upgraded; after the last user database is upgraded, the legacy instance can be removed.
Preserve the Server and Instance name	Preserves the same server and instance name.
Server consolidation project		The upgraded instance can be placed upon the consolidation server, after which the old server can be taken out of service.
Applications required to run in parallel with the original and new instances of SQL Server		Can maintain both systems with production transactions until ready to turn off the original system.
New server hardware or operating system		The upgraded instance can be put upon the new server, after which the old server can be taken out of service.
Shortage of disk space in production	Because there is only one resulting instance, there is less additional dataspace required than is possible with two complete resulting instances running side by side.
Legacy Server cannot meet the SQL Server 2008 Setup requirements for installation	None - not supported .	Only possible with side-by-side upgrade to a new server which meets setup requirements.
Changing to a earlier edition of SQL Server 2008	None - not supported.	Only possible with side-by-side upgrade.
Upgrade a 32-bit version of SQL Server 2000 or 2005 to a 64-bit version of SQL Server 2008	None - not supported .	Only possible with side-by-side upgrade.
Upgrade a 64-bit version of SQL Server 2000 or 2005 to a 32-bit version of SQL Server 2008.	None - not supported.	Only possible with side-by-side upgrade.
Target instance is SQL Server 2000 SP3a and only one downtime window is available		Transferring data to a new instance may be faster than the two steps required to apply the required SQL Server 2000 SP4 and then upgrading to SQL Server 2008.
Upgrading from a nonclustered legacy instance of SQL Server to a clustered instance of SQL Server 2008	None - not supported.	Only possible with side-by-side upgrade.
Upgrading from SQL Server 7.0	None - not supported; would need first to upgrade to SQL Server 2000 or 2005.	Can be done in one direct upgrade by using manual data transfer.
Upgrading multiple instances	Generally faster because data transfer and configuration steps are handled by Setup.
Upgrading very large databases (VLDBs)	Setup converts existing data files automatically; no data transfer steps are required.	Can control the timing of several steps and also the rollback if it is necessary.
Upgrade Testing		Re-testing might be easier because the legacy instance of SQL Server does not have to be rebuilt. Testing can be done while legacy system still supports production applications. SQL Server Profiler can be used to capture SQL commands against the legacy system and used to play back against the new instance of SQL Server to verify that everything is working well.
Data must be transformed during the upgrade window		Data transformation tools such as SSIS can be used to transform data as it is being transferred from the legacy instance of SQL Server to SQL Server 2008.
Localization: change of SQL Server language		Enables upgrade to SQL Server 2008 with a different language from the legacy instance of SQL Server. Note: this issue is not to be confused with collation settings. This applies to the localized language of the SQL Server product.
Upgrading Notification Services	None - not supported.	Only possible with side-by-side upgrade. Requires Notification Services backward compatibility add-in.
Application integration	Simpler because the same server name, instance name, and database security settings are preserved by Setup, without manual intervention.	Applications can be moved from legacy system in a staged manner instead of all at the same time. Even though your system might have passed all validation and acceptance test, a problem could still occur. If a problem does occur, then you will be able to roll back to the legacy system.
Server Integration	Might be simpler because linked server, replication, and log shipping settings can be preserved, depending on the SQL Server version being upgraded.

Sql Server 2008 Upgrade Technical Reference Guide : http://www.microsoft.com/downloads/details.aspx?FamilyID=66d3e6f5-6902-4fdd-af75-9975aea5bea7&displaylang=en

Sql Server 2005 SP3 disponibile per il download

Francesco Diaz — Tue, 16 Dec 2008 21:23:00 GMT

E' scaricabile qui. Il documento di riferimento con la lista dei bug corretti e le informazioni aggiuntive per chi ha già applicato i CU 10 e 11 è disponibile qui.

Cumulative Update #11 per Sql Server 2005 SP2 - Articolo 958735

Francesco Diaz — Tue, 16 Dec 2008 12:01:18 GMT

Contiene tutte le hotfix rilasciate dopo l'uscita del service pack 2 di Sql Server 2005. Il documento che ne parla è disponibile qui.

Sql Server 2005 Failover Cluster su Windows Server 2008 : MS DTC

Francesco Diaz — Thu, 23 Oct 2008 12:42:42 GMT

Per la configurazione di Sql Server 2005 in cluster su Windows Server 2003 era necessario configurare MSDTC come risorsa del cluster. Con Windows Server 2008 non è più necessario perchè MSDTC può essere eseguito localmente anche in presenza della feature di failover cluster.

Una novità interessante è che, se necessario, istanze multiple di risorse MSDTC possono esistere in un cluster Windows Server 2008 per distribuire meglio il carico delle transazioni distribuite.

Come fare per :

Abilitare l'accesso alla rete per le transazioni MSDTC :

To enable Network DTC Access for MS DTC transactions

1. Open the Component Services snap-in.

To open Component Services, click Start. In the search box, type dcomcnfg, and then press ENTER.

2. Expand the console tree to locate the DTC for which you want to enable Network MS DTC Access.

3. On the Action menu, click Properties.

4. Click the Security tab and make the following changes:

• In Security Settings, select the Network DTC Access check box.

• In Transaction Manager Communication, select the Allow Inbound and Allow Outbound check boxes.

5. Click OK.

Abilitare le eccezioni su Windows Firewall per MSDTC

Open Windows Firewall.
To open Windows Firewall, on the Start menu, click Control Panel. In Control Panel, do one of the following:
- Under Security, click Allow a program through Windows Firewall.
- If Control Panel is in Classic view, click Windows Firewall.
On the Exceptions tab, select the Distributed Transaction Coordinator check box.
Click OK.

Risorse aggiuntive

http://technet.microsoft.com/en-us/library/cc730992.aspx - Descrizione di MS DTC su Windows Server 2008.

http://support.microsoft.com/kb/953170/en-us - Un webcast sulla configurazione di Sql Server 2005 in cluster.

Aggiornamento della policy di supporto di Sql Server 2005 e 2008 in ambiente virtuale - articolo 956893.

Francesco Diaz — Mon, 13 Oct 2008 11:39:00 GMT

L'ultimo aggiornamento è datato 7 Ottobre. Oltre al supporto per Hyper-V trovate informazioni relative al supporto per altri vendor con il programma SVVP. L'articolo può essere consultato qui.

Le seguenti restrizioni vengono applicate quando Sql Server viene eseguito in ambiente virtuale :

• Guest Failover Clustering is not supported in a virtual machine. Guest Failover Clustering is when you create a SQL Server failover cluster inside a virtual machine where the nodes are running as a virtual machine.

• The virtual machine must be running an operating system that is supported for the specific SQL Server version and edition and that is supported for virtualization.

• The SQL Server product must be a supported version under its current Microsoft Support Lifecycle policy. For more information about Microsoft Support Lifecycle policies, visit the following Microsoft Support Web site: http://support.microsoft.com/?pr=lifecycle

Risorse aggiuntive :

Requisiti hardware e software : http://technet.microsoft.com/en-us/library/ms143506.aspx

Load Test

Francesco Diaz — Fri, 25 Jul 2008 18:16:18 GMT

Vi segnalo un Load Test tool per Sql Server. Al momento la versione di Sql supportata è la 2005 e il software presenta alcune limitazioni :

Limitations

Only supports code that operates against a single database with a single connection.
Prepared statements are not supported.
The tool cannot (yet) configure and capture the trace for you, it requires you to use the SQL Profiler yourself to get a trace. With SQL 2005 it is possible to automate this.
Not (yet) integrated into Visual Studio or the DB Pro edition.
The tool has only been tested in an English environment, it is unlikely to work correctly in other environments, particularly with dates. In a future version this could be resolved by requiring the ExistingConnection event class, which lists language and date format.
The tool does not support the XML data types.
InputOutput parameters that are initialised with a NULL cannot be distinguished from Output-only parameters, so they are treated as Output only.
When the trace passes a NULL to a binary parameter (e.g. image, binary, varbinary) the generated code will generate a runtime error. The generated code needs to be modified to pass SqlBinary.Null. The custom code generation extensibility point can be used to work around this.
Positional parameters passed to SQL statements (as opposed to stored procedure calls) are not supported.