tuning oracle sql queries

: = Time_limit_default,Ask_name in VARCHAR2: = NULL,Description in VARCHAR2: = NULL)RETURN VARCHAR2; Case:DECLAREMy_task_name VARCHAR2 (30);My_sqltext CLOB;BEGINMy_sqltext: = ' SELECT 1 from dual ';My_task_name: = Dbms_sqltune. Create_tuning_task (Sql_text = My_sqltext,Bind_list=>sql_binds (ANYDATA. Convertnumber (9)),user_name = ' Noap ',Scope=> ' comprehensive ',Time_limit = 600,Task_name = ' Sql_tuning_test ',Description=> ' TUNING TASK ');END; BEG

Label:A recent project involves data-table queries of large data volumes. The total data table is about 700 million-2 billion, the primary key to establish a global unique index, the partition policy is hash partition + range partition, most of the time the query condition hit record more than million, a single return to the previous XX record. The following experiences are summed up in the tuning process:(

August 14, 2017, a city of Oracle related Scheduler ETL extraction speed is very slow, the average SQL statement execution time of about 9 seconds, if shown:650) this.width=650; "Src=" http://img.blog.csdn.net/20170814133720856?watermark/2/text/ ahr0cdovl2jsb2cuy3nkbi5uzxqvd3d3x3h1zv94aq==/font/5a6l5l2t/fontsize/400/fill/i0jbqkfcma==/dissolve/70/gravity/ Center "width=" "style=" border:0px;vertical-align:mi

Tags: process optimizer consolidation requires merging auto overwrite session accessThe full execution order of the SELECT statement:The full execution order of the SQL SELECT statement: 1. The FROM clause assembles data from different data sources; 2. The WHERE clause filters the record rows based on the specified criteria, 3, the GROUP BY clause divides the data into multiple groupings, 4, uses the aggregation function for the calculation, 5, uses t

1. New tuning Set Object ***************************************** ---Authorize grant administer any SQL TUNING SET to Scott;---Delete the existing stsbegin Dbms_sqltune. Drop_sqlset (sqlset_name = ' ocpyang_sts '); end;/---new Stsbegin dbms_sqltune. Create_sqlset (sqlset_name = ' ocpyang_sts ', Sqlset_owner = ' SCOTT ', description = ' ocpyangtest '); end;/---Vi

time and reduce the syntax errors caused by the column ambiguity. 14. Replace distinct with exists:When submitting a query that contains one-to-many table information, avoid using DISTINCT in the SELECT clause. You can generally consider replacing with exists Example: (Low efficiency) Select from where d.dept_no = e.dept_no; Efficient Select from where exists (select1fromwhere d.dept_no = e.dept_no); exists makes queries faster because the RDBMS co

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

SQL queries the nclob field of oracle, sql1_lenclob Use the CONTAINS keyword to query the NCLOB Field SELECTFORMATTED_MESSAGEFROMFOC. TBL_LOGWHERECONTAINS (FORMATTED_MESSAGE, p_FORMATTED_MESSAGE)> 0; Oracle clob field insertion In oracle, four lobs types are available: blob

The SQL Tuning toolset (SQL Tuning set,sts) is an integral part of the Oracle 10g SQL Tuning Advisor feature. Each tuning toolset contains o

SQL statement implementation that limits the number of data queries in ORACLE and SYBASE databases I. OverviewFor some software that needs to deal with a large amount of data through databases, processing performance is very important. In order to ensure that the software can process all data without crashing, the idea of batch processing came into being. The spe

SQL statement implementation that limits the number of data queries in ORACLE and SYBASE databases. oraclesybase I. Overview For some software that needs to deal with a large amount of data through databases, processing performance is very important. In order to ensure that the software can process all data without crashing, the idea of batch processing came int

:A. Needs to be queried from the database: Totalrecords. "SELECT COUNT (*) from TableName"B. The most basic needs of user-provided: PageSize and Pagenow. (Personally think this is the premise of pagination algorithm)C. Derived from other variables: TotalPages, Beginrow and Endrow. (it needs to be calculated that Beginrow and endrow are required for paging queries, TotalPages is the information that the page needs to provide). Specific formula for cal

By default, SQL Server queries are case-insensitive. That is, whereaABC is the same as wherea 'abc '. By default, SQL Server queries are case insensitive. That is, where a = 'abc' is the same as where a = 'abc '. However, we can determine whether the case is case sensitive by using the method. Method 1: Alter t

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