sql server varchar max performance issues

than using cursors. If development time permits, a cursor-based approach and a set-based approach can all be tried to see which method works better. 28. Set NOCOUNT on at the beginning of all stored procedures and triggers, set NOCOUNT OFF at the end. You do not need to send a DONE_IN_PROC message to the client after each statement that executes the stored procedure and trigger. 29. Try to avoid large transaction operation and improve the system concurrency ability. When using constraints and t

In the last 3 articles, we discussed a list of different queries that reflect the current state of the server. Initial SQL Server performance issues (1/4): Server overview Initial

from being cracked by malicious attacks. It has no effect on space and performance. N setting is better:Since there is no impact on space and performance, we only need to consider the business needs. I have analyzed Microsoft databases, most of which are set to 256. We will also see 64,128,512, max, etc, it may be easy to remember. Examples of

SQL Server uses cursors to deal with the extremely competitive performance of Tempdb-DBA issues-required by programmers, tempdb-dba Competition in SQL Server tempdb allocation is a common issue for DBAs. Almost all DBAs now know h

, which avoids longer locking of the system tables.25. Avoid using cursors as much as possible, because cursors are inefficient and should be considered for overwriting if the cursor is manipulating more than 10,000 rows of data.26. Before using a cursor-based method or temporal table method, you should first look for a set-based solution to solve the problem, and the set-based approach is generally more efficient.27. As with temporary tables, cursors are not unusable. Using Fast_forward cursors

analysis. The following script will help us list a session that has opened a transaction but is not active, that is, open a transaction, but no statements have been executed for the last 30 seconds. 1 /***************************************************************************************** 2 STEP 4:list The Open session with transaction which are not active3 ****************************************************************************************/ 4 SELECT es.session_id,5 Es.login_name,6 es. HO

Label:In the initial SQL Server performance issue (1/4), we learned how to quickly check the number of tasks that are running on the server instance and the number of IO waits. This is a lightweight script that does not put any pressure on the server, even if the

Label:Original: Initial SQL Server performance issues (1/4): Server overviewWhen you are a DBA, many people will complain to you: "This program data loading and snail, you see the server is not a problem?" "There are many reasons

tested before the conclusion.In addition, see SqlServer2014 (SQL 2014 new feature Introduction series-In-memory OLTP (In-memory OLTP)) also made a large adjustment, basically support memory storage, can be asynchronously quickly stored in memory, the scheme for the current device, I'm afraid it won't work.Other, later in the search process learned how to achieve a copy, copy the scene of the application Mode (actual combat).To replace

analysis. The following script will help us list a session that has opened a transaction but is not active, that is, open a transaction, but no statements have been executed for the last 30 seconds.1 /*****************************************************************************************2 STEP 4:list The Open session with transaction which are not active3 ****************************************************************************************/4 SELECTes.session_id,5 Es.login_name,6Es.host_nam

server| Problem | performance 1. To optimize the query, you should try to avoid full table scan, first consider the where and the order by the columns involved in the establishment of the index. 2. The null value of the field in the WHERE clause should be avoided as far as possible, or it will cause the engine to discard the use of the index for a full table scan, such as:Select ID from t where num is nullY

Background:New servers that require increased performance monitoring to find that performance metrics cannot be read through PowerShellWorkaround: Open the Registry Editor by going to the Start Menu and selecting Run ..., then type "regedit", and click the OK button. Navigate to the HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\SecurePipeServers\winreg registry key. Right click on t

Original: SQL Server 2012 exception Issue (ii)--performance issues caused by installation mediaProblem Description: Production environment A database is upgraded from SQL Server R2 to SQL