SQL Server

Top keyword: write in front of the field after selectFor example, you want to display the first 5 records of a query, as follows:Select Top 5 * from StudentIn general, top is the same as the order byOrder by uses the order by after the name of the

Recently, you need to set the default value for DateTime to the current time in SQL Server 2012.Set through a visual window instead of writing the GETDATE () function in an SQL statement, or writing ' 2022-2-2 22:22:22 ' in an SQL statement.At first,

Permissions required to run SQL Server Profiler (performance) *********/--eg. --Use the Trace account (performancetest) to track SQL Server events.  --Create a Trace login account (performancetest) and grant its ALTER trace and view SERVER State

1. Select statement Constituent element 1.1 SELECT *Avoid using SELECT *When you want to list all columns in the SELECT clause, it is a convenient way to refer to ' * ' Using a dynamic SQL column. Unfortunately, this is a very inefficient approach.

What is a self-increment columnThe ID column can be set to self-increment in SQL Server. That is, you do not need to specify a value for the ID, the column is automatically assigned a value by SQL Server, and the value of each new column ID is added

Event Cause: Recent research and development reaction, a database from 08 to 12 environment, the occurrence of write operation delay problem;Event Analysis: After troubleshooting problems such as system resource contention, preliminary analysis may

Original: Anatomy of SQL Server end article about Internals Viewer source codeAnatomy of SQL Server end article about Internals Viewer source codeYou may have used the Internals viewer software.Widget for viewing SQL Server Internal Data page

Original: Anatomy of SQL Server 13th integers storage format in row compression and page compression (translated)Anatomy of SQL Server 13th integers storage format in row compression and page compression

first, the concept of the indexThe purpose of the index: our data query and processing speed has become a measure of the success of the application system standards, and the use of indexes to speed up data processing speed is often the most commonly

a system in a pharmaceutical industry requires a collection of different contact types based on the patient's contact record ID, and the effect is like this--patient exposure to record information, a patient can have n different contact records, and

1.DataTable DT; Assuming the field is name, DT has saved the datadt.rows[0]["name"] = = System.DBNull.Value; Determines whether the name field of the first row of data is empty2.DataTable DT; Assuming the field is name, DT has saved the datadt.rows[0

The first step:How much memory is used for each type of resource.SelectClerks.type,SUM (clerks.virtual_memory_reserved_kb) as reserve,SUM (clerks.virtual_memory_committed_kb) as [Commit],SUM (clerks.awe_allocated_kb) as [awe],SUM

The Projkyaddin is a management Studio plug-in that installs packages of more than 500 KB and is compatible with SSMs 2005, SSMs 2008, SSMs R2, ssms 2012, SSMs 2014, the function is to provide a shortcut to the script file on the hard disk in the

during the implementation of the XENDESKTOP5 project, it was found that the XENDESKTOP5 version of the database mirroring transaction log was large, in XENDESKTOP4 and The problem does not exist in the XENAPP version, so I'm going to

First, the concept of bookmark searchBookmarks can help SQL Server quickly direct from the nonclustered index entry to the corresponding line, but I can actually say a few words about it.　　If the table has a clustered index (the section structure),

Problem A new subscription node is added to a library, and some applications need to be sliced into a new subscription repository to distribute the load. When the app switches, there is an app that starts in less than 30 seconds each time, and

In general, table expressions do not have a positive impact on performance or adversely affect performance.Note the following code style:SELECT COUNT (DISTINCT as numcusts from (SELECTyear(OrderDate), CustID from as D (OrderYear, CustID)

Original: SQL Server uses RowNumber () built-in functions with the over keyword to implement a common paging stored procedure (support for single-or multiple-table node-search-Sets paging)SQL Server uses the RowNumber () built-in function with the

The performance improvement of a system is not only the task of performance tuning in the trial operation or maintenance stage, but also not just the development phase, but the whole software life cycle needs attention, effective work can be

The batch log recovery mode of the SQL Server recovery model. Do you want to know why the transaction log file is getting bigger and bigger? Transaction logs are sometimes larger than your actual database files, especially in the case of application