toad sql tuning

Oracle SQL tuning procedure The full name of SQL is Structured Query Language (Structured Query Language ). SQL is an industrial standard database query language used in the middle of 1980s. Do not confuse SQL with commercial products such as Microsoft

Label:Original: SQL Server performance Tuning (i)--judging system resource bottleneck from waiting stateView the status of all SQL Server tasks at that time (sleeping, runnable, or running) through the DMV2005, 2008 provides the following three view Tudon detailed query: DMV Use Sys.dm_exec_requests Returns information abo

Chapter 2 procedural performance tuning of PL/SQL applications I. Reasons for PL/SQL Performance problems When the execution efficiency of PL/SQL-based applications is low, it is usually caused by poor SQL statements and programming methods, poor understanding of PL/

In 10 Gb, Oracle launched its own auxiliary SQL optimization tool: SQL optimizer (SQL Tuning Advisor: STA), which is a new DBMS_SQLTUNE package. To use the STA, make sure that the optimizer is in CBO mode. However, I think this tool is only suitable for those who do not fully understand

, next we will add some of the SQL Server parallel operations, Then analysis of our daily write additions and deletions to these operators to optimize the items, interested in advance attention, about 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 privat

Client protocols Aliases The Protocol is the same as (2). You can specify more configurations. 3. sp_configure/reconfigure Displays or changes the global configuration settings of the current server. Many configurations need to be set through sp_configure. Syntax: sp_configure [ [ @configname = ] 'option_name' [ , [ @configvalue = ] 'value' ] ] reconfigure For example: To configure advanced options with sp_configure, you must first run sp_configure when the "show advanced options" op

at the statement level, the hint syntax is:/*+ bind_aware*/;Ø about outlines: In the scene of outlines existence, the ACS will fail whether the system level is enabled or the statement level is enabled through hint;6. Conclusion:New features of Oracle Database 11g The ACS feature provides an easy way to efficiently share SQL statement execution plans with bound variables. Because ACS produces a new execution plan only if the binding variable value se

statement that will form a specific plan, and the resulting specific plan is not always optimal, which is related to the content distribution, the amount of data, the type of data in the database's existing data tables, and the statistics that are used to record these details.All optimal planning choices are based on existing statistical information, and if our statistics are not updated in a timely manner, then the optimal execution plan will not be the best, and sometimes the worst.Reference

statements. Using adbc in the abap environment is similar to using JDBC in the Java environment. The reports and transactions they write can use any available interface to access the database. Use DB2 parameters in SAP Open SQL SAP supports a batch of DB2 parameters that can be added to Open SQL statements to affect how natural SQL statements generated from Open

. server.2005. Technical Insider "series 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 intere

How to use STA (SQL tuning advisor), tuningadvisor1. manually generate SQL tuning advisor1. SQL text format:DECLAREMy_task_name VARCHAR2 (30 );My_sqltext CLOB;BEGINMy_sqltext: = 'select * FROM DBA_SEGMENTS where owner = ''clic' AND SEGMENT_TYPE = ''table ''';My_task_name: =

Use Cases I remember when I was tuning for a company, the person in charge sent me a bunch of business T-SQL scripts, I am still calm in the face of massive scripts, although I do not understand the internal complex business, however, we have to focus on the key "slowness" of the problem. We will filter them out based on the "slowness" of the query and optimize them one by one. Won't the problem be solved q

. Orderid,o1. Freightfrom Orders o1where O1. Freight>( SELECT AVG. O2. Freight) from Orders O2)The goal of SQL execution is to query orders that have more than the average shipping charge in the order.The clause that extracts the average freight here is a completely independent subquery that executes independently of the main query. At the same time here we take advantage of a scalar computation (AVG) so that it returns exactly one row.Look at the

SQL Auto-tuning is an Oracle-brought tuning tool that provides solutions.This time I mainly introduce the following automatic SQL tuning tools: Automatic SQL tuning (Automatic

gp4.1 and previous SQL with not in will be executed with Cartesian product, using nested join, very poor efficiency Not in== use the left join to go back to the table Association to implement Example select * from test1 where col1 not in (select col2 from test1)Switch select * from test1 a left join (select col2 from test1 group bycol2) b on a.col1=b.col2 where b.col2 is nullThe run time is increased from more than 30 seconds

. server.2005. Technical Insider "series Conclusion This 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 inte

would recommend adjusting your index design to create an overlay index to ensure the stability of the plan. But forcing a specific execution plan is just a temporary fix-you still have to fix the root cause of your problem. Summary Don't get me wrong: query storage in SQL Server 2016 is a great feature that will help you understand planned regression more easily. It will also help you "temporarily" enforce a specific execution plan. But the goal of p

[Oracle] oracledba6 SQL Tuning sets, oracledba6tuning You want to use the SQL Tuning Advisor to generate recommendation S for badly written SQL statements in your development environment. W Hich three sources can you select for the advisor to analyze? (Choose Three .) A

Tag: Time Condition number column arch OSI user CTE codeIn section 1.5 of the SQL Tuning Basics Overview 05-oracle Index Type and introduction, several "Common index execution plans" are mentioned: Index full Scan: Fully scanned indexes, block read, orderedIndex range Scan: Range sweep of indexIndex fast full Scan: Fast all scans of indexes, multiple reads, unorderedINDEX full SCAN (Min/max): Query

Performance Tuning for mysql SQL statements Performance Tuning for mysql SQL statements In server development, there are sometimes requirements on the concurrency, and sometimes an SQL statement, such as a stored procedure, affects the speed. Now, if the execution of an