with nolock in sql server performance

parameterization.Sqlserver:sqlstatistics/failed auto-params/secNumber of failed automatic parameterization attempts per second. the value should be very small. Note that in later versions of SQL Server, automatic parameterization is also known as simple parameterization.Sqlserver:sqlStatistics/batch requests/secNumber of Transact- SQL command batches received pe

If you suspect that computer hardware is the main cause of affecting the Performance of SQL Server, You can Monitor the load of the corresponding hardware through SQL Server Performance Monitor to confirm your guesses and identify

When we want to count the total number of records in a datasheet, we use the T-SQL function count (*). If this function is executed in a large table containing millions of rows, it can take a long time to return the total number of records in the entire table, which results in a decrease in query performance. First, the general approach: using the count () function Each database administrator knows how to

Tags: info include distributed apps a little view Collection graphical interface operation NBSP;NBSP;NBSP;OTANBSP;NBSP;NBSP; One of the primary responsibilities of the database administrator is to continuously monitor SQL Server performance. There are several reasons for monitoring, including performance, storag

] ')This allows you to see the foreign keys in the SalesOrder table (if any)But if so, I do not have to query every table, Google to find a solution, with a SQL statement to do all, as follows:--using Sysreferences--Delete foreign keyDECLARE @SQL VARCHAR( -)DECLARECur_fkCURSORLOCAL forSELECT 'ALTER TABLE ['+ object_name(Fkeyid)+ '] Drop constraint' + object_name(ConstID) fromsysreferences--Delete all foreig

(user_lookups), if these two values are small, you might consider dropping the index.When you restart the SQL Server service, the various counters in the Sys.dm_db_index_usage_stats system view are initialized to null values. In addition, whenever data is detached or closed (for example, because Auto_Close is set to ON), all data rows associated with the database are deleted. When an index is first used, i

to archive, partition, table sharding, etc) Software System (operating system optimization, database system configuration, resource planning and monitoring, etc) Hardware infrastructure (Device specifications, hardware performance, Server Load balancer, Disaster Tolerance, etc) SQL statement writing, indexing and statistics, transactions and locks, application a

Permission management is involved in program development. The system uses an integer to record user permissions. The permission level is set: Level1 1 Level2 2 Level3 4 Level4 8 Level5 16 Level6 31 Level7 32 Level8 64 Level9 127 Level10 128 Level11 255 Level12 65535 In the database, if a user A has a permission level of 1, his three

system into multiple nodes, each node's processor can only access its own local resources, is a completely unshared architecture. Data exchange between nodes requires software implementation. Its advantage is that scalability is very good, the disadvantage is that data exchange difficulties with each other, the need to control a lot of software work to achieve communication and task allocation, scheduling, for the general enterprise applications is too complex, inefficient. NUMA (non-uniform

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 SQL

; } /// ///User Account/// Public stringUserName {Set;Get; } /// ///User Password/// Public stringPassWord {Set;Get; } /// ///Nickname/// Public stringNickname {Get;Set; } /// ///Encrypted Salt/// Public stringSalt {Set;Get; } /// ///whether to freeze/// Public BOOLIsFrozen {Set;Get; } /// ///Balance/// Public decimalBalance {Set;Get; } /// ///Department/// Public stringDepartme

can specify whether the event can be "lost". This means that if there is not enough memory to buffer an event, it can be discarded directly. The default setting is to allow a single event to be discarded, but you can also allow the entire event buffer to be lost (for sessions where the event buffer is quickly filled up), or even to specify that no events should be lost.You should take extra care when using the last option, because it forces the code that fires the event to wait until there is e

fragmentation has occurred? Execute the following SQL statements in your database. (Sql2005 or earlier database, replace the database name "adventureworks") Select object_name (DT. object_id) tablename, Si. nameindexname, DT. avg_fragmentation_in_percent asexternalfragmentation, DT. avg_page_space_used_in_percent asinternalfragmentationfrom (select object_id, index_id, avg_fragmentation_in_percent, avg_page_space_used_in_percent from sys. dm_db_index

Some common performance problems in SQL Server: 1. When optimizing the query, try to avoid full table scanning. First, consider creating an index on the columns involved in where and order. 2. Try to avoid using left join and null values. Left join consumes more resources than inner join because it contains data that matches null (non-existent) data. Therefore, y

Http://blog.csdn.net/tuoxie5431/archive/2010/01/19/5214010.aspx When executing SQL queries, the main bottlenecks are: CPU computing speed, memory cache size, and disk Io speed. For queries of large data volumes, the bottleneck is generally concentrated on disk Io and memory cache. In order to improve the efficiency of SQL queries, we need to minimize the number of data entries designed for queries-create a

Transferred from: http://www.cnblogs.com/MR_ke/archive/2010/08/25/1807856.htmlSQL 2005 Performance TuningSQL Server runs for a period of time, and as data accumulates, SQL runs less efficiently, and in order to use business system normal actions, IT departments often need to spend a high price on SQL tuning experts to

Label:Source: When SQL Server creates a composite index, the composite index column order affects the performance of the query Talk about composite indexes Write index blog Too much, has not wanted to write, there are two reasons:One is the suspicion that there are fried leftovers, brothers have said: Index, as long as the query criteria to build the index on the

frequently (by the way, it becomes a clustered index), and can better meet most of our needs. The auto-increment ID column is omnipotent. The Int type only occupies 4 bytes to fully meet the requirements of narrow indexes. The absolute sequential storage can effectively reduce index fragmentation, which fully conforms to our table habits, it is always correct to use an auto-increment ID column as the primary key. Here, the key columns of clustered indexes are mainly for query consideration. S

First, Introduction Recently, a customer has noticed a high counter (forwarded records/sec), with intermittent disk wait queue fluctuations. This article shares what is the forwarded record and discusses in principle why the forwarded record creates additional IO. Second, the principle of storage In SQL Server, when data is stored as a heap, the data is unordered, and pointers to all nonclustered indexes

affected)(One row is affected)SQL Server execution time:CPU time = 0 ms, occupied time = 528 Ms.(Row 3 is affected)Table 'worktable '. Scan count 0, logical read 0, physical read 0, pre-read 0, lob logical read 0, lob physical read 0, lob pre-read 0.Table 'tb2 '. Scan count 3, logical reads 1002, physical reads 0, pre-reads 0, lob logic reads 0, lob physical reads 0, and lob pre-reads 0.Table 'tab1 '. 1 sc