openjson sql server 2014

million rows of data in the table, where A=1 has 10,000 data, where B=1 has 10,000 of the data, the selectivity of A and B is 1/100=0.01, and the estimated number of rows A and b in the where is changed to 0.01*0.01= 0.0001*100 = 100 rows, assuming that the data filtered by where a=1 and B=1 are the same 10,000 rows of data, the estimated number of rows is 100 and the actual number of rows is 10,000, which can cause performance problems due to inaccurate execution plans. Of course, this is a sm

needs to be restarted. in Object Explorer, right-click your server, and then click Restart. If you run a SQL Server agent, you must also restart the agent. Enable the SA logon nameEnable the SA logon name "security" , "login name", Right-click "sa" , then click . page, You may need to create a password for the login and confirm the pass

. Update Time: SELECT name AS index_name, STATS_DATE (object_id, index_id) AS update_dateFROM sys. indexes WHERE object_id = OBJECT_ID ('[Sales]. [SalesOrderDetail] '); -- view all statistics. Update Time: select s. name, STATS_DATE (s. object_id, stats_id) AS update_datefrom sys. stats s WHERE s. object_id = OBJECT_ID ('[Sales]. [SalesOrderDetail] '); -- view all statistics. Update Time: exec sp_helpstats n' [Sales]. [SalesOrderDetail] ', 'all' GO -- CREATE statistical information create statis

In EF, it is convenient to use LINQ for paging, if we have an EMP table with the following structure:public class Emp { [Key] public Guid No {get; set;} public int Age {get; set;} [Required] [Stringlength ()] public string Name {get; set;} }If we are paging, we generally use the skip and take methods, where the simplest line of code is as follows:MContext.Emp.OrderBy (emp = EMP). Name). Skip (6). Take (3);If we are using EF6, when using

will be very long, sit good bench, melon seeds snacks and so on ... No nonsense, go to the Chase technical Preparation database version for SQL SERVER2008R2, using Microsoft's previous case library (Northwind) for analysis, part of the content will also be applied to another Microsoft ... Read the full text posted @2014-12-29 21:50 fingertip flow reading (1573) | Comments (6) Edit

display server state. 连接到其他计算机（SQL Server 配置管理器）.">To start, stop, pause, resume, or configure services on another computer by using SQL Server Configuration Manager, see Connect to another computer (SQL

Tags: www class div utility best important find traditional creatSource: Statistics in SQL Server histogram for no coverage of predicate predictions and changes in the estimation strategy (SQL2012--GT;SQL2014--GT;SQL2016) The source of this article: http://www.cnblogs.com/wy123/p/6770258.html Statistics have written a few related articles, feeling or not enjoyable, about the statistics of the problem, rece

and column B are highly correlated, the estimated number of rows will be very inaccurate.For example, if the table contains 1 million rows of data, where a = 1 has 10 thousand rows, and where B = 1 has 10 thousand rows, then the selectivity of A And B is 1/100 = 0.01. In the Where clause, the estimated number of rows associated with A And B is 0.01*0.01 = 0.0001*1 million = 100 rows, if the data filtered by where a = 1 and B = 1 is the same 10 thousand rows, the estimated number of rows is 100,

PS: Title is a bit long ...When you upgrade SQL Server R2 to SQL Server 2014, you encounter the following rule validation errors: Rs_validdatabaseversion Check that the version of the report server database ca

example, the difference is negligible because the table involved in the scan is small. In my opinion, this feature is rarely used in real-world scenarios. Can only say there is better than nothing. The only thing that would have been to execute the plan was to let SQL Server decide for itself. Microsoft claims that this query hint can greatly improve the performance of query statements using spool in high

the former. It is mainly used to protect the multi-thread concurrent access to some specific memory objects. The Spinlock is exclusive. Only one thread can own it at a time. The goal of the Spinlock design is extremely fast and efficient. How does a Spinlock work internally? First, it tries to obtain the Lock of an object. If the target is occupied by other threads, it will round-robin (spin) there for a certain amount of time. If the lock is not available, sleep for a while and continue with s

Tags: blog http os io 2014 problem ar sqlEnvironment:SQL Server2008 R2SQL Server Management StudioWhen you test your deployment project today, you find that you cannot access SQL Server remotely. The scenario is that when Management Studio is connected to DB, the Server name

= I.data_space_idjoin sys.filegroups As FG on fg.data_space_id = I.data_space_idwhere objectproperty (p.object_id, ' ismsshipped ') = 0ORDER by ObjectName, IndexID, PartitionNumberCategory: MSSQL Database Tags: table partition, partition table good text to the top of my collection this article the? Previous: Optimization analysis of SQL statements? Next post: SQL

Objective: with the release of SQLServer2014 on July 15, 201441, the performance of SQL server has been greatly improved, so that more and more users and DBAs are using other databases gradually turn to MSSQL. Here is a personal Blog for you to answer Objective: with the release of SQLServer2014 on June 1, the performance of SQL

[1] connection problems (example) [Microsoft Access] Constr = "DBQ = c: \ daTa \ clwz. mdb; DRIVER = {Microsoft Access Driver (*. mdb )}" [Microsoft SQL Server] Constr = "DRIVER = {SQL Server}; SERVER = host; DATABASE = mydata; uid = sa; pwd =" [2] similar functions(Example

the Name of the current Language. Select @ lock_timeout; -- returns the current lock timeout setting for the current session (MS) Select @ max_connections; -- returns the maximum number of user connections allowed by the SQL Server instance at the same time. Select @ MAX_PRECISION AS 'max Precision '; -- returns the Precision level used by the decimal and numeric data types. Select @ SERVERNAME; -- Name of

.3. Use " start –> input cmd–> Enter –>netstat-an | find" 1433 " Enter ", did not see the IPv4 1433 port open, and see IPv6 1433 Open, also thought is IPv6 reason. Uninstalling the IPV6 is still not working. 4. Modify the TCP port in TCP/IP in SQL Server configuration Manager under SQL Server network configurations.

When my SQL 2014 virtual machine was migrated, the LUNs holding tempdb were deleted. After the operating system of the virtual machine is started, SQL Server instance does not start up. Check event Log for error. So, I found this article. The goal is to force SQL

"SQL Server replication requires a real server name to connect to the servers, please specify the actual server name" go? SQL Server replication requires an actual server name to connec

Http://www.cnblogs.com/stswordman/p/3936584.html http://www.cnblogs.com/stswordman/p/3252549.html#3229105 Http://blogs.msdn.com/b/psssql/archive/2012/09/07/how-it-works-sql-server-alwayson-lease-timeout.aspx http://blogs.msdn.com/b/alwaysonpro/archive/2014/11/26/ Diagnose-unexpected-failover-or-availability-group-in-resolving-state.aspx https://msdn.microsoft.co