index performance tuning in sql server

Original: SQL Server performance optimization included columnsSQL Server performance optimization included columnsGuide: Data number optimization query has always been a relatively hot topic, niche in this area can only be regarded as an introductory student. ThisOh, God, we

1. The problem system has a module that needs to query data in the Oracle database. Currently, this is achieved by creating a linked server. The current query statement of limit is a simple 1. The problem system has a module that needs to query data in the Oracle database. Currently, this is achieved by creating a linked server. SQL

SQL Server Performance Analysis-deadlock detection database blocking statementsWork in the database often appear in memory, found an articleRefer to Csdn, China Wind (Roy) A deadlock article block: One of the transactions is blocked, other transactions wait for the other party to release their locks, and can cause deadlock problems.People: China Wind (Roy) refer

fill factor as the new default value for the index or any other rebuilt nonclustered index (because the clustered index has been rebuilt). If FILLFACTOR is 0,DBCC dbreindex The specified start fillfactor will be used when the index is created.Also enter the command in Query Analyzer:DBCC DBREINDEX (' database_name.dbo.Employee ', ', 90)Then use DBCC SHOWCONTIG to view the results of the refactoring index:DBCC showcontig scanning ' Employee ' table ...Table: ' Employee ' (1195151303); Index id:1

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

What is an index? Index is an important tool to improve query performance. index is to add a small amount of data required by the query statement to the index page. In this way, you only need to access the pages of a few indexes when accessing data. However, indexes are not omnipotent in improving query performance, nor are they as good as creating more indexes. The index is missing.WhereThe efficiency of c

; +----+-------------+-------+-------+---------------+---------+---------+------+------+-------+ | id | select_ Type | Table | Type | possible_keys | key | key_len | ref | rows | Extra | +----+-------------+-------+-------+---------------+---------+---------+------+------+-------+ | 1 | Simple | film | index | NULL | PRIMARY | 2 | NULL | 55 | NULL | +----+-------------+-------+-------+---------------+---------+---------+------+------+-------+ 1 row in Set ( 0.00 se

1. The question The system has a module that needs to query the data in the Oracle database. It is now implemented by establishing a linked server. SQL Server access Oracle implementation can refer to this article http://www.cnblogs.com/gnielee/archive/2010/09/07/access-oracle-from-sqlserver.html The current query statement is a simple query with a where condi

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

compression is 167M, the size of the table after compression is only 40% of the original table, the effect is obvious, and because most of the table's fields are only IDs, the relative repetition value is not too much.However, we see that the size of the index varies substantially, so we continue to compress the index:5. Compression indexAlter index idx_tb_wcb_id on Tb_wcbrebuildwith (Data_compression=row)6, the comparison after the index compressionsp_spaceused ' ms_visit_qst_opt '/*name

I usually don't pay much attention to database-related things. I feel good to see this article: Speed Up SQL Server Apps Learn 10 useful tips and tricks that help boost SQL Server application performance-and streamline development and deployment as well The following ar

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

In the initial SQL Server performance issue (2/4), we discussed the list of waiting resources or running session scripts. In this article we will look at how to list blocked sessions with specific information.1 /******************************************************************************************/2 CREATE FUNCTION [dbo]. Dba_getstatementforspid3 ( 4 @spi

] ')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

DC--perform connection, most recently executed query informationCross apply sys.dm_exec_sql_text (dc.most_recent_sql_handle) DTJoin Sys.dm_exec_sessions DS on dc.session_id=ds.session_idwhere Ds.login_name= ' LCGS609999 '--where ds.program_name = '. Net SqlClient Data Provider 'ORDER by Dt.textCopy Code Copy Code--Clears all cached data in the buffer poolDBCC dropcleanbuffersGO--Clears all cached execution plans in the buffer poolDBCC FreeproccacheGO--statistical information, implementation pla

SQL Server performance optimization included columnsGuide: Data number optimization query has always been a relatively hot topic, niche in this area can only be regarded as an introductory student. ThisOh, God, we'll talk about it. The function of the database contains columns and the optimization effectquote an explanation from the next MSDN section:when all col