postgresql tuning

Optimized tuning of TCP/IP and kernel parametersThere are many ways to optimize TCP/IP and kernel parameters under Linux, the configuration of parameters can greatly improve the performance of the system, and can also be optimized according to specific scenarios, such as time_wait, DDoS attacks and so on.The following configuration is written in sysctl.conf and can be used with sysctl-p.The relevant parameters are for reference only, the specific valu

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

PostgreSQL registration Start and Stop unmount batch processing script, postgresql Batch Processing Register to start pg_install.bat: echo offset PGSQL_DIR=%~dp0if not "%PGSQL_HOME%"=="" ( if not "%PGSQL_HOME%"=="%PGSQL_DIR%" ( echo PGSQL_HOME=%PGSQL_HOME% != PGSQL_DIR=%PGSQL_DIR% goto pg_ends )) else ( set PGSQL_HOME=%PGSQL_DIR% echo PGSQL_HOME must be set as PGSQL_DIR=%PGSQL_DIR%

PostgreSQL code analysis, query optimization, canonicalize_qual, postgresql Here, we have finished sorting out the part of the regular expression. The reading order is as follows: I. PostgreSQL code analysis, query optimization, canonicalize_qual Ii. PostgreSQL code analysis, query optimization, pull_ands () and pull

in 10g, Oracle launched its own SQL optimization aids : SQL Optimizer (SQL Tuning Advisor :STA) , it is the new Dbms_sqltune package. Use the STA to make sure that the optimizer is in CBO mode. but I think the use of such tools, only for the people who do not understand the tuning of SQL, do not feel that the tool can solve the problem. SQL says exactly what is expressed is a business, how the tool can und

Detailed description of the PostgreSQL Partition Table (partitioning) application instance, postgresql Partition Table Preface Vertical table sharding is required in the project, that is, data is split into n tables according to the time interval. PostgreSQL provides the partition table function. A partition table actually Splits a large logical table into severa

Onewget https://ftp.postgresql.org/pub/source/v9.2.4/postgresql-9.2.4.tar.gzSecond, installation:# Install dependent packagesYuminstall-y perl-extutils-embed readline-devel zlib-devel pam-devellibxml2-devel libxslt-devel openldap-devel Python-devel gcc-c++ Openssl-devel cmake-yTARZXVF postgresql-9.2.4.tar.gzCD postgresql-9.2.4./configure--prefix=/usr/local/pgsql9

Label:2.2 Xlog and ReplicationIn this chapter, you have learned that the transaction log for PostgreSQL has made all changes to the database. The transaction log itself is packaged as an easy-to-use 16MB segment.The idea of using this change set to replicate data is not farfetched. In fact, this is a logical step in the development of each relational (or even non-relational) database system. Other parts of the book, you will see in many ways how the

Label:Brief introduction We can manage the PostgreSQL database through some graphical interface management programs, such as Pgadmin, to create new objects by visual or command line, delete and edit existing objects (such as directories, schemas, tables, etc.) and access them through JDBC or ODBC. Interface operation: To open a connection to a service, select the desired service in the tree, double-click it, or use the Connect on the Tools menu.In the

PostgreSQL tutorial (6): Functions and operators (2), postgresql Operators 6. Pattern Matching: PostgreSQL provides three methods for implementing pattern matching: SQL LIKE operator, closer SIMILAR TO operator, and POSIX-style regular expression.1. LIKE:Copy codeThe Code is as follows:String LIKE pattern [ESCAPE escape-character]String not like pattern [ESCAPE e

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

JVM tuning-New Generation and jvm tuning New Generation A new generation of Java virtual machines, including eden space and two dedicated vor spaces. The new generation is used to store newly created objects. The new generation features fast object updates and produces a large number of "Dead objects" in a short time ". Garbage collection for young generations is called secondary garbage collection (minor