aed tuning

Tags: sdn is ola visible reason water personal tuning tunToday, while watching Tri Hua's SQL optimization book, he saw a case in which he solved the SQL performance problem, and Tri Hua the teacher successfully positioned the problem and solved it. Here, on the basis of Tri Hua teacher analysis and positioning, do further analysis and reasoning, so that we can study and discuss together, the following is a brief description of the case scenario. 1. SQ

ObjectiveIn the previous article we analyzed the role of statistical information in the database, and we have learned how the database uses statistics to control the distribution of the contents of tables in the database. Children's shoes are not clear and can be clicked for reference.As a tuning series of articles, the index of the database is certainly not less, so this article we began to analyze this piece of content, about the basic knowledge of

Tags: upd alt has meaning tab logic for good problem useObjective In the previous article we analyzed the role of statistical information in the database, and we have learned how the database uses statistics to control the distribution of the contents of tables in the database. Children's shoes are not clear and can be clicked for reference. As a tuning series of articles, the index of the database is certainly not less, so this article we began to an

MySql performance tuning policy and mysql tuning policy This topic provides detailed parameter descriptions for my. cnf configuration. The sample configuration is as follows: # Cat my. cnf # MySQL client library initialization. [Client] Port = 3306 Socket =/tmp/mysql. sock Character-set-server = utf8 # The MySQL server [Mysqld] Init_connect = 'set names utf8' // sets utf8 encoding for connectin

Common SQL Tuning Tips and SQL Tuning tuningtips Create an appropriate index (refer to correct database index creation) Replace OR with UNION (applicable to index columns) Replace in and not in with exist and not exist Do not declare numbers in character format (this will invalidate the index and generate a full table scan) Do not use select * (list each column after select)

JVM tuning summary, jvm Tuning Auxiliary InformationJVM provides a large number of command line parameters and prints information for debugging. There are mainly the following: -XX: + PrintGCOutput Format: [GC 118250 K-> 113543 K (130112 K), 0.0094143 secs][Full GC 121376 K-> 10414 K (130112 K), 0.0650971 secs] -XX: + PrintGCDetailsOutput Format: [GC [DefNew: 8614 K-> 781 K (9088 K), 0.0123035 secs] 1

Oracle tuning uses related SQL, oracle tuning related SQL Select * from v $ session where username is not null;Select username, count (username) from v $ session where username is not null group by username;Select count (*) from v $ process;Select value from v $ parameter where name = 'processs ';Select count (*) from v $ session where status = 'active ';Select name, VALUE, DISPLAY_VALUE from v $ parameter

with a graphical performance detection tool. Ability to monitor memory, threads, class loading, virtual machine information, and moreVisual VM is a multi-in-one graphical performance detection tool that integrates a variety of new capability detection tools. Can replace some of the JDK's own tools, if JSTATE,JPS, etc.The Mat full name Memory Analyzer is a powerful Java heap analysis tool capable of analyzing heap memory leaks and viewing memory usage information.The Jprofiler tool is a powerful

Database Tuning tutorial (4) Explain performance analysis command, tuning explain In the previous chapter, we learned how to find slow queries and record statements into logs. How can we know where statement problems occur after slow queries are found. This chapter describes how to use the database performance analysis commands provided by Mysql to analyze SQL statements. Ii. Explain commands for database

Jvm-related parameters, tuning, and jvm parameter tuning Common jvm parameters are as follows: -Xmx1024m: Set the JVM maximum available memory to 1024 MB.-Xms1024m: Set JVM to enable the memory to be 1024 MB. This value can be set to the same as-Xmx to avoid JVM re-allocating memory after each garbage collection.-Xmn512m: Set the young generation size to 512 m. Memory size of the entire JVM = size of the yo

Meizu mobile browser compatibility tuning best practices, compatibility tuning Best PracticesProblem 1: Non-position: absolute container height: 100% does not take effect, leading to bottom location dislocation 1: The actual height of the container is rendered as 0. 2: Node 1 style contains position: relative; height: 100%; but the height in meizu mobile browser is rendered as 0Node 2 defines bot

Database Tuning tutorial (4) Explain performance analysis command, tuning explain In the previous chapter, we learned how to find slow queries and record statements into logs. How can we know where statement problems occur after slow queries are found. This chapter describes how to use the database performance analysis commands provided by Mysql to analyze SQL statements. Ii. Explain commands for database

Supports SQL tuning and SQL TUNING A friend of mine found me a few days ago and said that an SQL Performance problem exists to see if it can be optimized. The process is as follows: Snow Leopard 9:35:10 Are you there? Orchid island master 15:07:39 I forgot. What's the matter? Snow Leopard 15:07:49 Hmm Snow Leopard 15:07:54 Database Optimization Problems Orchid island master 15:08:04 Oh, you said. Snow Leopa

MySql Performance Tuning (5) demonstration of using a proper lock mechanism for table locks, mysql Tuning MySql locks take the following forms: 1. Table-level locks; low overhead, fast locking; no deadlock; large lock granularity, the highest probability of lock conflict, the lowest concurrency. The MyISAM engine belongs to this type. 2. Row-level locks: high overhead and slow locking; deadlocks may occur;

MySql Performance Tuning (4) Quick table structure modification and mysql Tuning 1. Modify the varchar type To meet your needs, change varchar (6) To varchar (8). A better method is not to use altertable modify, but to use the following steps: A. Create A temporary table and set varchar to varchar (8) as follows: B. Replace the. frm table structure file. C. Check it. To be tested in

Database Tuning tutorial (5) Roles of indexes and types of indexes, tuning IndexesIii. Index In the previous chapter, we learned how to use explain to generate a query execution plan (QEP), so as to discover problems with the statement. Three results returned by explain are related to the index (possible key, key, and extra). It can be seen that the index plays a significant role in improving the query eff

Three Tomcat modes and concurrent tuning, and tomcat Tuning Three Tomcat modes and concurrent optimization.Three Tomcat running modes are available: BIO, NIO, and APR. These three types are described as follows: 1. bio The default mode has very low performance and has not been optimized or supported.2. nio Using java asynchronous io Nursing Technology and noblocking IO technology. To run in this mode, dir

Linux system tuning authoritative guide, linux tuning Guide 1. Disable SELINUX.1.1 modify the configuration file to make SELINUX disabled permanently effectiveSed's # SELINUX = enforcing # SELINUX = disables # G'/etc/selinux/config ==> restart the system to take effect1.2 temporarily disable SELINUX[Root @ hadoop01 xningge] # setenforceUsage: setenforce [Enforcing | Permissive | 1 | 0]==> The number 0 indic

Need for Performance Tuning In this world of SAP programming, ABAP is the universal language. in most of the projects, the focus is on getting a team of ABAP programmers as soon as possible, handing over the technical specifications to them and asking them to church n out of the ABAP programs within the "given deadlines ". Often due to this pressure of schedules and deliveries, the main focus of making a efficient program takes a back seat.

JVM tuning-calculate the active data size and jvm tuning Active Data Active Data, sometimes called survival data, refers to the size of long-lived objects in the Java heap when the application is in stable running state. In other words, the space occupied by the Java heap after FullGC in the stable running state of the application (memory usage ). 1. Importance of active data computing The calculation of t