tuning sql server

Tags: Profiler Performance Performance Analyzer tuning performance calibrationSQL Server Profiler-performance tuningPerformance has enough reason to become a hot topic. Today's business is fiercely competitive, and if users think that an application is too slow, they will immediately turn to another vendor. To meet the user's requirements, SQL Trace loads the eve

. Because the latter will not generate a large number of locked table scans or index scans.If you want to check whether a record exists in the table, do not use count (*) as inefficient and waste server resources. It can be replaced by exists. For example:If (select count (*) from table_name where column_name = 'xxx ')Can be written:If exists (select * From table_name where column_name = 'xxx ') You often need to write a t_

ConclusionThis article first to this bar, short, easy to understand, this article mainly introduces the query plan of the joint operators, the next we analyze SQL Server parallel operations, in multicore hyper-threading gathered today, see SQL How server uses parallel operations to maximize the use of existing ha

calculation.In fact, the goal of bitmap computing is very simple: pre-filtering , because our statement requires the result item to compare more than 10000 rows of data, in the thread behind us to take the parallel scan of the way to obtain the data. Due to the large amount of data, the various threads in the process of the completion of data acquisition time is different, in order to avoid the slow execution of a thread, resulting in overall congestion, the index introduced a bitmap operation

released, the data page will not be in the memory of the data cache, This causes the memory problem to be the bottleneck of the disk. PAGEIOLATCH_EX is write data, this is generally the disk write speed obviously keep up, and memory is not directly related. Here is the resource wait time for query pageiolatch_x: Select Wait_type, waiting_tasks_count, Wait_time_ms, Max_wait_time_ms, Signal_wait_time_ms from sys.dm_os_wait_stats wherelike' pageiolatch%' order by Wait_type Through the above

After setting the SET statistics profile, you will return to the Execution plan table, through which you can understand the process of statement execution and understand if SQL Server chooses the correct execution plan to determine the tuning direction!1. Returns the table field description:Rows: The actual number of rows returned in each step of the execution pl

SQL Server database self-optimizing release time under large data volume:2013-12-17 15:19:00 Source: Forum anonymous Keywords: database development1.1: Add secondary data filesStarting with SQL SERVER 2005, the database does not generate the NDF data file by default, generally there is a master data file (MDF) is enou

an execution plan, and stored in a database of SQL statements, is a collection of control flow language, the speed of course fast. 48, the return value of the function is not too large, this overhead is very large. A user-defined function that executes as a cursor consumes a large amount of resources if a large result is returned with a stored procedure. 49, as far as possible to avoid repeated access to the same or several tables, especially the lar

Label:Original address: Http://social.technet.microsoft.com/wiki/contents/articles/4995.sql-server-columnstore-performance-tuning.aspxSQL Server's Columnstore index is a new version of SQL Server release that improves query performance for the Data Warehouse, and this article explains the performance

Label:In today's scale OLTP system, it is a good way to solve the problem by replicating multiple copies in order to alleviate the single point of reading and writing pressure in the database, especially the read pressure.The SQL Server transactional replication transactional Replication is the most common form of replication we take. Some of the previous articles always introduce some basic constructs,Lack

, one is not perfect function also dare to take Out (2000) The second functional architecture of the outstanding design makes the function has a strong continuity and Scalability (2005 2000 of the function to retain and improve). The optimization tool is simple to use 1: Use SQL Server Porfiler (Event Viewer) to record all the steps of the operation database in the business system and save it as a working

1. Check the database space usage to see which tables are consuming larger disk spaceExecute the following statement:SelectO.name, SUM (p.reserved_page_count) asReserved_page_count, SUM (p.used_page_count) asUsed_page_count, SUM ( CaseWhen (p.index_id2) Then (p.in_row_data_page_count+P.lob_used_page_count+p.row_overflow_used_page_count)Elsep.lob_used_page_count+P.row_overflow_used_page_count End) asDataPages, SUM ( CaseWhen (p.index_id2) then Row_countElse 0end) asrowcounts fromsys.dm_db_partiti

, how can we tell which tables need to be indexed and which are not?Typically, SQL Server executes a query script with an existing index, and if no index is found, it is automatically generated and stored in the DMV (dynamic management view). This information is purged whenever the SQL Server service restarts, so it is

SELECT TOP 1000O.name as table name, I.name as index name, i.index_id as index ID, dm_ius.user_seeks as Search times, Dm_ius.user_scans as Scan count, dm_ius.user_lookups as lookup times, dm_ius.user_updates as update number, p.tablerows as table row count, ' DROP INDEX ' + QUOTENAME (i.name)+ ' on ' + QUOTENAME (s.name) + '. ' + QUOTENAME (object_name (Dm_ius. object_id)) as ' DELETE statement 'From Sys.dm_db_index_usage_stats Dm_iusINNER JOIN sys.indexes i on i.index_id = dm_ius.index_id and D

server| Performance 1, in the program, to ensure that in the implementation of the function of the foundation, minimizing the number of accesses to the database, minimizing the number of accesses to the table by searching the parameters, minimising the result set, and reducing the burden of the network; the ability to separate the operations as much as possible, to improve the response rate each time; When you use

Label:11g new Features-automatic SQL tuning (Automatic SQL Tuning) In Oracle 10g, an automatic SQL Tuning feature was introduced. In addition, ADDM monitors SQL statements that capture

11g new Features-automatic SQL tuning (Automatic SQL Tuning)In Oracle 10g, an automatic SQL Tuning feature was introduced. In addition, ADDM monitors SQL statements that capture high lo

Tags: ash text results SQL tuning SRC completion need to end TunA few days ago, a user developed QQ to find me, as follows:The free Dolphin. 16:12:01The island owner, my SQL can not find the results, could you help me see?Orchid Island Main 16:12:10How long is the result?The Free Dolphin 16:12:17How long has not produced the result, has not seen the result.Orchid

in 10g, Oracle launched its own SQL optimization aids : SQL Optimizer (SQL Tuning Advisor :STA) , it is the new Dbms_sqltune package. Use the STA to make sure that the optimizer is in CBO mode. but I think that using this tool is only suitable for people who don't understand SQL