--Find the spinlock types select map_value, map_key, name from sys.dm_xe_map_values where name = 'spinlock_types' order by map_value asc --Example: Get the type value for any given spinlock type select map_value, map_key, name from sys.dm_xe_map_values where map_val...
For example, when the values in a column are mostly NULL and the query selects only from the non-NULL values, you can create a filtered index for the non-NULL data rows. The resulting index is smaller and costs less to maintain than a full-table nonclustered index defined on the...
SELECT TOP 1 DatabaseName = DB_NAME() ,TableName = OBJECT_NAME(s.[object_id]) ,IndexName = i.name ,user_updates ,system_updates -- Useful fields below: -- , * INTO #TempUnusedIndexes FROM sys.dm_db_index_usage_stats s INNER JOIN sys.indexes i ON s.[object_id] = i.[object...
Optimization (determining the execution plan) takes place before the database knows what values will be substituted into the query. An execution plan cannot, therefore, depend on what those values are. For example: SELECT infoFROM tablesWHERE ...AND somecolumn BETWEEN DECODE(:loval, 'ALL', som...
SELECT DISTINCT Salary FROM Employee ORDER BY Salary DESC LIMIT 1,1) AS SecondHighestSalary ***注意在上面这个子查询临时表方法中最后是没有From 的 ***一般此时我们会用dual作为规范代替,dual是最小单位临时表 常用语特殊语句的查询和计算:eg "select 22*33 from dual" from Employee...
Sub SelectX1() Dim dbs As Database, rst As Recordset ' Modify this line to include the path to Northwind ' on your computer.Setdbs = OpenDatabase("Northwind.mdb")' Select the last name and first name values of all 'recordsinthe Employees table.Setrst = dbs.OpenRecordset("SELECT LastNa...
Decrease the values of the configuration parameters that define allocation of memory, includingASLHEAPSZif UDFs are involved in the failing statement. Install more random access memory (RAM). If a remote procedure was invoked, ensure that the remote procedure uses a local variable space that is le...
Arrays - Finding Highest and Lowest Values in an array asenumerable is not a member of system.data.datatable Asign an array to a Combobox.Items --VB.NET Assign 'Enter' key to a button? Assign DBNull.Value to a variable, or: write NULL to MSSQL database Assign text box input to ...
To copy table data to the clipboard, click the column header (for all column data) or select specific cells and press Ctrl+C; to copy the column header text along with the table data, press Ctrl+Shift+C. To sort the display of rows by values within a column, double-click the column...
Lesson 3 SQL SUM Use the SQL SUM function to total the numerical values in a particular column. Start Now Lesson 4 SQL MIN/MAX See examples using the SQL MIN and MAX functions to select the highest and lowest values in a particular column. ...