postgresql performance tuning parameters

System performance has always been a hot topic. Do operation of the past few years have been engaged in performance tuning, writing this article is also a summary of the work.The first step in tuning is to say why tuning? That is, the system analysis, analysis also need to h

Hardware preparation environment: Hard Disk: 16 SAS15KRAID5 with 512 MCacheCPU: AMD4 core two memory: 16 GB software environment: Operating System: RedHatAS4.62.6.9 Hardware preparation environment: Hard Disk: 16 SAS 15 K RAID5 with 512 MCacheCPU: AMD 4-core two-core memory: 16 GB software environment: Operating System: RedHat AS4.6 2.6.9 Hardware preparation environment: Hard drive: 16 SAS 15 k raid 5 with 512 MCache CPU: AMD 4-core two Memory: 16 GB Software environment: Operating System:

Hardware preparation environment: Hard drive: 16 SAS 15 k raid 5 with 512 MCache CPU: AMD 4-core two Memory: 16 GB Software environment: Operating System: RedHat AS4.6 2.6.9-67. ELsmp Mysql: 5.0. Performance Tuning based on different scenarios is as follows: Scenario: Write operations (insert, query, and delete) are intensive, and the data capacity far exceeds the memory size (minimum is more than GB, or ev

Article Source: http://hi.baidu.com/top2top/blog/item/0bea951600a16050f2de322b.html apache2.0 prefork and worker module Performance Tuning The performance improvement of Apache 2.0 is the most attractive. On UNIX systems that support POSIX Threads, Apache can use different MPM to run in a mix of multi-process and multi-thread modes to enhance the scalabi

lead to the generation of swap, and the system performance will be greatly reduced.Of course, if there is 4 GB memory, the probability of 50 such large queries at the same time should be very small. However, you need to understand the relationship between max_connections and work_mem.Interpretation of parameters is visible: http://www.varlena.com/varlena/GeneralBits/Tidbits/annotated_conf_e.html and http:/

1. JPS (Java Virtual machine Process Status Tool)JPS is primarily used to output process state information running in the JVM-Q does not output the class name, jar name, and parameters passed in the Main method-m output parameters that pass in the Main method-L OUTPUT The full name of the main class or Jar-V Output parameters for incoming JVM2. JstackJstack is us

Io is very relevant, when the free buffer waiting in the v$session_wait of the entry is very small or not, Explain the DBWR process of your system will be enough, do not need to adjust, there are many items of free buffer wait, your system must feel very slow, then your DBWR is not enough, the resulting wio has become your database performance bottlenecks, the solution is as follows: A.1 to increase the write process while adjusting the db_block_lru_

application and should be adjusted by analyzing the actual time and frequency of garbage collection. If the heap is large in size, complete garbage collection can be slow, but the frequency is reduced. If you match the size of the heap with the need for memory, the collection will be complete quickly, but will be more frequent. The purpose of the heap sizing is to minimize the time spent in garbage collection to maximize the processing of customer requests for a specific period of time. In the

PHP Optimization for PHP optimization is mainly related to the php.ini in the main parameters of the reasonable adjustment and settings, the following we will look at some of the php.ini in the performance of a large number of parameters should be set. # Vi/etc/php.ini(1) PHP function is disabled to find:Disable_functions =This option can set which PHP functions

and optimized the performance of Hadoop clusters deployed in virtualization and Physical Mode on the same scale. The experiment shows that the virtualized Hadoop cluster can well support the production environment.Performance Comparison between a virtualized environment and a physical environment Figure 1 shows the deployment style of the Performance Tuning Test

tables are only affected by max_heap_table_size System parameters are affected . when the server creates an internal temporary table ( whether in memory or on disk ), Create_tmp_tables variables will increase . If you created an internal temporary table on disk ( Whether it was initially created or converted by in-memory ), The Create_tmp_disk_tables variable will increase . in some cases, the use of temporary memory tables is limited , and disk

servers, the parameters of the last few lines can be a good way to reduce the number of time_wait sockets, but for Squid, the effect is not small. This parameter controls the maximum number of time_wait sockets, preventing squid servers from being dragged to death by a large number of time_wait sockets.Tuning is complete, then press to see the effect of it.# Netstat-n | awk '/^tcp/{++y[$NF]} END {for (w in y) Print W, Y[w]} ' established 968Is

support Create compressed data page19, can dynamically turn off the InnoDB update metadata statistics function: Pollution buffer pool, annlyze table and Show table status will also read the table metadata pollution buffer pool20. Enhanced copy function21. Relay Log Self-repair22, open InnoDB Strict check mode23, dynamically change the system configuration parameters, new parameters can be changed dynamical

open the table for each thread, and the larger the number of connections, the greater the value will be.Table_open_cache>= max_connection*2, when some tables are open, you need two file descriptors, such as MyISAM table, index, temp table, and so on. Self-Linking query statements, additional open a file for the table (the targeted setting is to find all the most complex query statements related to the database, including the self-linking left/right/inner/outer join and group statistics statemen

This document is a translation of section 1.1 of the IBM Redbook Linux Performanceand Tuning guidelines.Original address:http://www.redbooks.ibm.com/redpapers/pdfs/redp4285.pdfOriginal Eduardo Ciliendo, Takechika Kunimasa, Byron BraswellThe translation is as follows:1.1 Linux Process ManagementProcess management is one of the most important functions of the operating system. Efficient process management can ensure a smooth and efficient operation of a

Original link: Spark Streaming performance tuning　The Spark streaming provides an efficient and convenient streaming mode, but in some scenarios the default configuration is not optimal, and even the external data cannot be processed in real time, and we need to make relevant modifications to the default configuration. Because of the reality of the scene and the amount of data is not the same, so we can not

default.Copying files between OSS, currently only supports copying object and does not support copying multipart.General recommendationsJobs * Parallel and CPU cores are 1:1,2:1, but not too bigToo many concurrent numbers will directly fill the network card, the CPU will be crowded. It is recommended to observe the environment CPU, network, process/thread condition while concurrencyReferenceOssutil Large File Breakpoint continuationPlease add a link to the original link descriptionThis article

http://www.ibm.com/developerworks/cn/websphere/library/techarticles/0707_wudan/#resourceswas Application Server Environment Building Practice GuideHttp://blog.chinaunix.net/uid-20687159-id-1894968.htmlWas performance tuningHttp://wenku.baidu.com/link?url=6pbNwpnXyJ8rCk-ciNVg_bRYGxyTlVXRtM0OlehhunLWTAo1MjWjZ_ Yy9vnshfxqnxrcbrzx4lkohkg163ijtqjcal5g9d0qulxr3b99bliHttp://tech.ccidnet.com/art/322/20030603/48448_1.htmlhttp://yishueitian326.blog.163.com/blog

oracle| Data | database | Performance Oracle is a high-performance database software. The user can adjust the parameters to achieve the optimization of performance. Performance optimization is mainly divided into two parts: first, the database administrator through the adjus

SQL Server Performance Tuning 3 Index MaintenancePreface The previous article introduced how to improve database query performance by creating indexes, which is just the beginning. If you do not need proper maintenance in the future, the indexes you have previously created may even become a drag-and-drop attack and a helper for database