sql tuning advisor

indexed fieldsH, do not use functions on indexed fieldsI, do not make multi-field connections to indexed fields3. Return only the data you needThe return data to the client needs at least the database extracts data, the network transmits the data, the client receives the data as well as the client processing data and so on, if returns the unnecessary data, will increase the server, the network and the client invalid labor, its harm is obvious, avoids this kind of event to need to notice:A, in t

summary data is based is updated frequently, it is easier to use a view than to write SQL every time 2. Create a ViewThis is how the CREATE view is defined in the MySQL documentation: CREATE [OR REPLACE] [algorithm = {UNDEFINED | MERGE | TempTable}] [definer = {User | Current_User}] [SQL SECURITY {definer | INVOKER}]VIEW view_name [(column_list)]As Select_statement[With [cascaded | LOCAL] CHECK

ELSEStatement_end_offsetEND -Statement_start_offset)/ 2) fromSys.dm_exec_sql_text (sql_handle)) asQuery_text--, Plan_handle,db_name(qp.dbid), Qp.query_plan fromsys.dm_exec_query_stats Crossapply Sys.dm_exec_query_plan (plan_handle) QPORDER by(total_logical_reads+Total_logical_writes)/Execution_countDESC--indexes that have not been usedSELECTO.nameobject_name --Table name, I.name index_name--Index name, I.type_desc--whether the clustered index, S.user

Tags: nts BSP One execution plan ext CSDN Pull performance issues Recently because very busy, has been busy to develop the company's products and customer affairs, assorted, busy, so, for a long time did not come here to write things, this two days for the customer optimized a system, optimize the CPU continued hoisting full, leading to the system card, the application system can not be used normally, There is a SQL execution plan is a bit large

fromV$thread T, V$parameter vWHEREV.name= 'Thread' and(V.value= 0 ORt.thread#=To_number (v.value))) I, (SELECTVALUE fromV$parameterWHERENAME= 'user_dump_dest') D;3.2 Using the Tkprof command to beautify the generated trace fileHere is what I often use, for more detailed instructions on the tkprof command, you can see the tkprof command directly enter.Tkprof xxx.trc xxx.txt Explain=system/Oracle sys=nReference URL: http://www.eygle.com/archives/2004/10/use_sql_trace_to_diagno

decomposition, it seems necessary to sort out a directory ....SQL Server Tuning Series BasicsSQL Server Tuning Series Basics (Summary of common operators)SQL Server Tuning Series Basics (Union operator summary)SQL Server

Original: SQL Server Tuning Series Basics (Index operations Summary)ObjectivePrevious articles we introduced how to view the query plan, the introduction of common operators, the way of parallel operations, interested can click to view.This article will analyze in SQL Server, how to use the first indexed items for query performance optimization, by understanding

Use of the 1.explain plansql> explain plan for delete from T_jingyu; Explained.sql> select * FROM table (dbms_xplan.display); Plan_table_ OUTPUT------------------------------------------------------------------------------------------------------------------- -------------------------Plan Hash value:1368587462------------------------------------------------------------- ----------| Id | Operation | Name | Rows | Cost (%CPU) | Time |--------------------------------------------------------------

1. Import the trace file into the tableSELECT IDENTITY (BIGINT11 as RowNumber,* into TableNamefrom fn_trace_gettable ('trace.trc'default)2. Querying for statements with large CPU overheadSELECT Top -Total_worker_time/Execution_count asAvg_cpu_cost, Plan_handle, Execution_count, (SELECT SUBSTRING(text, Statement_start_offset/2 + 1, ( Case whenStatement_end_offset= -1 Then LEN(CONVERT(nvarchar(Max),text))* 2 ELSEStatement_end_offsetEND -Statement_start_offset)/2) fro

Select * from Table (dbms_xplan.display_cursor (sql_id = ' 9s7pt2ay4t3jg '));DeclareL_result_name Varchar2 (30);L_task_name Varchar2 (£): = ' task_name_9s7pt2ay4t3jg_1 ';L_sqlid Varchar2 (£): = ' 9S7PT2AY4T3JG ';BeginL_result_name: = Dbms_sqltune.create_tuning_task (sql_id = L_sqlid,Scope = ' comprehensive ',Time_limit = 60,Task_name = L_task_name,Description = ' Task to tune a query on a specified table ');Dbms_sqltune.set_tuning_task_parameter (Task_name = L_task_name,Parameter = ' Time_limit

Oracle SQL Tuning Health Check ScriptWe focus on the performance of database system, the main task of database tuning is to optimize SQL. Good data architecture design, with application system middleware and writing a beautiful SQL, is the future of the system on-line no fat

Books Online logical operators and physical operator references Refer to the book SQL. server.2005. Technical Insider "series Conclusion This article mainly introduces some of the methods of index operation, mainly describes the way we usually apply when writing statements, and to cite a few examples, as a point, in fact, we usually write in the statement is nothing more than this article introduced in the various ways of change, patchwork.

attention, on the SQL Server performance tuning of the content is very broad, followed by the analysis in the article.If you have any questions, you can leave a message or private messages, and look forward to an in-depth study of your child's shoes with SQL Server. Learn together and progress together.At the end of the article to give a few links, it seems nece

Original: SQL Server Tuning Series basics (Parallel operations Summary chapter II)ObjectiveIn the previous article we described how to view the parallel running of a query plan.In this article we then analyze the parallel operations of SQL Server.Gossip less, directly into the topic of this article.Technical preparationAs in the previous few, the

Original: SQL Server Tuning Series Basics (Summary of common operators)ObjectiveIn the previous article we looked at how to view the query plan, this article will introduce the analysis techniques in the query plan we looked at, as well as several of our commonly used operator optimization techniques, the same emphasis on the master of basic knowledge.In this article, we can understand how we normally write

Label:Original: SQL Server Tuning Series Basics (Summary of common operators)ObjectiveIn the previous article we looked at how to view the query plan, this article will introduce the analysis techniques in the query plan we looked at, as well as several of our commonly used operator optimization techniques, the same emphasis on the master of basic knowledge.In this article, we can understand how we normally

When it is determined that application performance problems can be attributed to one or several time-consuming statements, tuning these statements is the responsibility of the database administrator or database application developer. Statement tuning is one of the essential skills for dealing with databases.When you face a "problem" statement, how should you analyze its problem, and finally achieve the purp

Label:Original: SQL Server Tuning Series Basics (Union operator summary)ObjectiveIn the last two articles, we describe how to view the query plan, and some of the common optimization techniques for join operators, and we summarize how the federated operators are used and how to optimize them.Talk less and go straight to the subject of this article.Technical preparationBased on the

First, SQL tuning and query optimizerDatabase performance tuning generally begins with the discovery, analysis, and resolution of problems in SQL statement execution, which is collectively referred to as SQL Tuning (

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 hardware resources to improve performance, is interested in advance attention, the content o