The BULK INSERT statement imports formatted data directly into a table or view of your choosing. The main advantage of this statement is that is minimally logged if the correct recovery model is choosen. Peforming a transaction log backup after each bulk insert reclaims the log space that was used. This statment has many parameters that can alter how the statement executes. Today, I am going to demonstrate the parameters that I think are most useful. We will be working again with the Boy Scouts of America (BSA) hypothetical database.…
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Import & Export Data – Part 1
There are not many real life databases that do not import data from external sources or do not export data for delivery to external targets. I am going to devote a series of talks on different ways to perform these functions. The INSERT statement is the easiest way to load small sets of static information into a database. We will be working again with the Boy Scouts of America (BSA) hypothetical database. The first example loads the rank table with a data. We can see the auto-increment surrogote key is…
Temporary Tables – Part 5
Today, I am going to talking about common table expressions. A common table expression (CTE) is a temporary result set that is defined within the execution scope of a single DML statement. A CTE is simular to a derived table in which the results are not stored as an object; However, CTE’s can be recursive or built upon other CTE’s. The WITH key word is used to indicate the start of a CTE and needs to be preceeded with a semicolon. The rest of the syntax is like a stored…
Temporary Tables – Part 4
Today, I am going to talk about regular tables in tempdb. Please check out the Microsoft white paper on working with tempdb for a detailed discussion. The advantage of creating a table in tempdb is that it is persistent until the server is rebooted. Upon startup of SQL Server, tempdb is created again from scratch. One use of this technique is to have startup procedures create tables in tempdb that are used by an application program. One can leverage the fact that operations within tempdb are minimally logged. The major…
Temporary Tables – Part 3
Today, I am going to talk about table variables. In general, TSQL variables are defined by using the DECLARE key word and preceeding the variable name with a @ sign. Table variables are created by using the TABLE key word just after the variable name. The declaration following this key word includes column definitions — names, data types, and constraints. The only constraint types allowed in the declaration are PRIMARY KEY, UNIQUE, NULL, and CHECK. Indexes are a bi-product of a PRIMARY and UNIQUE constraints. The scope of a table…
Temporary Tables – Part 2
Today, I am going to talk about local and global temporary tables. A local temporary table is defined by using the CREATE TABLE syntax with the name of the table prefixed by one number sign #. The scope of the local temporary table is the current session or SPID. A global temporary table is defined by using the CREATE TABLE syntax with the name of the table prefixed by two number signs ##. The table is visible to all sessions. The scope of the global temporary table is the current…
Temporary Tables – Part 1
Today, I am going to be starting a series of articles on temporary tables. I will be focusing on derived tables. A derived table is a sub-query that is used to as input to the outer query. An table alias should be used outside the parenthesis to reference the inner query. I think of derived tables as a cross between temporary tables and dynamic views that go away after the query executes. The first example of a derived table creates the car ownership table for person a. Please see the…
Testing Alerts
Having set up system and performance alerting, it is now time to test those darn alerts to make sure they work! Alerting can notify a operator via email, paging, or a net send messages. Now adays, most people have a smart phone, not an old fashion pager. Therefore, I usually create a Active Directory group that has both the regular company email of the DBA group and their cell phone eqivalents which are usually the phone number @ provider name dot com. Today, I am going to talk about two…
Performance Alerts
Today, I am going to talk about setting up performance alerts so that you can notified when a server has issues. Basically, there are two types of performance alerts, SQL Server and WMI. I am going to use the sp_add_category system procedure to define a peformance category.
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-- Add a custom category for alerts EXEC msdb.dbo.sp_add_category @class=N'ALERT', @type=N'NONE', @name=N'[Alert By Performance]' ; GO -- Show Alert categoryes EXEC msdb.dbo.sp_help_category @class=N'ALERT' GO |
The sp_add_alert stored procedure is used to create the alert and the sp_add_notification stored procedure is used to associate the alert with an operator. This process is used below to show examples of both SQL and WMI performance alerts. The first type…
System Alerts
This article assumes that you configured both database mail and system operators. Please see my previous articles if you have not done these tasks already. Today, I am going to talk about setting up alerts for system error messages that might occur with your SQL server database. Since alerts have been around for a long time, most of this information is backward compatible with older software versions. The database engine defines the importance of an error messages with a severity level. Low importance errors are defined by levels 0 to…