shared memory segment

In the production environment's Em check ADDM, we will always see the suggestion to increase the SGA size recently. The current SGA is 4 GB, and we decided to increase it to 5 GB according to the suggestion. Environment:Dual-node RAC environment,

1. OnLine Operation Mode Off-Line offline mode)Quiescent static mode)On_Line online mode)Shutdown mode)Recovery mode) The OnLine system has the following working modes: Offline mode: OnLine is not running, and shared memory is not

Shmall is the size of all available shared memory, measured in pages. You can use getconfPAGESIZE to obtain the size of each page, generally, the 4096-byte shmmax is the maximum size of shared memory that can be used by a single segment. ip

[[email protected] ~]$ sqlplus / as sysdba SQL*Plus: Release 10.2.0.1.0 - Production on Thu Feb 26 18:46:02 2015 Copyright (c) 1982, 2005, Oracle. All rights reserved. Connected to an idle instance. SQL> SQL> SQL>

This article mainly introduces two sets of PHPAPC configuration files and detailed descriptions of parameters. For more information, see 1. install APCDownload http://pecl.php.net/get/APC-3.1.9.tgz The compilation parameters are as follows: The

Two sets of PHPAPC configuration files and detailed descriptions of parameters. 1. install APC to download pecl. php. the netgetAPC-3.1.9.tgz compilation parameters are as follows: Copy the code as follows:. configure -- enable-apc-spinlocks --

Tuning of JVM Optimizations large Memory paging (largepage) This article will be from the principle of memory paging, how to adjust the paging size two sections, to explain to you how largepage to the performance of the JVM, and at the end of the

1. Error handling-fprintf ()-Perror ()2. General-purpose I/O model-FD = open (pathname, flags, mode)-Numread = Read (fd, buffer, count)-Numwritten = Write (fd, buffer, count)-Status = Close (FD)-off_t lseek (int fd, off_t offset, int whence): Change

Kernel. suid_dumpable = 0Kernel. sercons_esc =-1Kernel. sysrq = 0Kernel. SEM = 250 32000 32 128Kernel. shmmni = 4096Kernel. Shmall = 2097152Kernel. shmmax = 33554432 Kernel. sercons_esc =-1Kernel. sysrq-timer = 10Kernel. sysrq-sticky = 0Kernel.

Environment Introduction: Dual-machine operating system: solaris10 database version: oracle11gR164bit current host name and IP: fly-db2192.168.20.21 current slave host name and IP: fly-db1192.168.20.20 Environment Introduction: Dual-machine

This document describes how to optimize the performance of RedHatEnterpriseLinux in the following aspects. 1) The LinuxProc file system is optimized by adjusting the Proc file system. 2) Linux performance diagnostic tool: describes how to use

Basic linux memory knowledge and related tuning SolutionsMemory is one of the important components in the computer and serves as a bridge to communicate with the CPU. All programs in the computer run in the memory, so the memory performance has a

I'll use a few blogs to summarize some of the ways in which you can communicate between processes in Linux, and I'm going to make this summary part of the beginning in every blog in this series.Ways to communicate between processes Pipeline

A shared memory introduction shared memory can be literally understood,share a piece of logical memory, let different processes access it, modify it。 Shared memory is a very efficient way to share and pass data between two running processes. Memory

The so-called shared memory is the fastest available IPC form that allows multiple processes to access the same piece of memory space. is designed for inefficient operation of other communication mechanisms. It is often used in conjunction with

ProcessProcess ConceptsProcessProcess is an executing procedure, which is only an informal statement. The process is not just program code, the program code is called the text segment (code snippet), also includes the current activity, the value of

After dbca*** all instances of the database, I wanted to clone the DB in rman duplicate mode, so I created the relevant directory under the $oracle_base directory Admin/dupl/adump ,admin/dupl/dpump    in use sqlplus normal connection idle instance,

Shmall and Shmmax parameters of the kernelShmmax= is configured with the largest memory segment size: This setting is much better than sga_max_size.Shmmin= the smallest amount of memory segmentShmmni= the total number of memory segment for the

Shared memory allows two or more processes to share a given store, because the data does not need to replicate back and forth, so it is the fastest inter-process communication mechanism. Shared memory can be implemented through the mmap () mapping

Shared memory agrees that two or more processes share a given store, and because the data does not need to replicate back and forth, it is the fastest inter-process communication mechanism. Shared memory can be implemented through the mmap ()