alert日志中出现ash size的警告

今天查看数据库的alert日志总出现了如下的警告。

Archived Log entry 202 added for thread 1 sequence 202 ID 0x1ed7a02c dest 1:
Sat Mar 15 01:37:30 2014
Completed checkpoint up to RBA [0xca.2.10], SCN: 267711453
Sat Mar 15 01:44:58 2014
Active Session History (ASH) performed an emergency flush. This may mean that ASH is undersized. If emergency flushes are a recurring issue, you may consider increasing
 ASH size by setting the value of _ASH_SIZE to a sufficiently large value. Currently, ASH size is 67108864 bytes. Both ASH size and the total number of emergency flushe
s since instance startup can be monitored by running the following query:
 select total_size,awr_flush_emergency_count from v$ash_info;
Sat Mar 15 01:45:00 2014
Beginning log switch checkpoint up to RBA [0xcc.2.10], SCN: 270149004
Thread 1 advanced to log sequence 204 (LGWR switch)
  Current log# 4 seq# 204 mem# 0: /TEST1/db03/oradata/PRDTEST1/redo_g4_m1.dbf
  Current log# 4 seq# 204 mem# 1: /TEST1/db04/oradata/PRDTEST1/redo_g4_m2.dbf
Sat Mar 15 01:45:11 2014

ash的size大小设置是隐含参数_ash_size中设置的。查看metalink(文档 ID 1385872.1)

CAUSE

Typically some activity on system causes more active sessions, therefore filling the ASH buffers faster than usual causing this message to be displayed. It is not a problem per se, just indicates the buffers might need to be increased to support peak activity on the database.

SOLUTION

The current ASH size is displayed in the message in the alert log, or can be found using the following SQL statement.

select total_size from v$ash_info;

Then increase the value for _ash_size by some value, like 50% more than what is currently allocated. For example if total_size = 16MB, then an increase of 50% more would be (16MB + (16MB * 50%)) = 24MB.

sqlplus / as sysdba alter system set "_ash_size"=25165824;

You can verify the change using the following select:

select total_size from v$ash_info;

原文发布于微信公众号 - 杨建荣的学习笔记(jianrong-notes)

原文发表时间:2014-03-19

本文参与腾讯云自媒体分享计划,欢迎正在阅读的你也加入,一起分享。

发表于

我来说两句

0 条评论
登录 后参与评论

相关文章

来自专栏飞扬的花生

jsencrypt参数前端加密c#解密

      写程序时一般是通过form表单或者ajax方式将参数提交到服务器进行验证,如何防止提交的请求不被抓包后串改,虽然无法说绝对安全却给非法提交提高了难度...

3879
来自专栏pangguoming

Spring Boot集成JasperReports生成PDF文档

由于工作需要,要实现后端根据模板动态填充数据生成PDF文档,通过技术选型,使用Ireport5.6来设计模板,结合JasperReports5.6工具库来调用渲...

1.2K7
来自专栏落花落雨不落叶

canvas画简单电路图

63311
来自专栏我和未来有约会

Silverlight第三方控件专题

这里我收集整理了目前网上silverlight第三方控件的专题,若果有所遗漏请告知我一下。 名称 简介 截图 telerik 商 RadC...

4045
来自专栏陈仁松博客

ASP.NET Core 'Microsoft.Win32.Registry' 错误修复

今天在发布Asp.net Core应用到Azure的时候出现错误InvalidOperationException: Cannot find compilati...

4878
来自专栏闻道于事

js登录滑动验证,不滑动无法登陆

js的判断这里是根据滑块的位置进行判断,应该是用一个flag判断 <%@ page language="java" contentType="text/html...

6988
来自专栏一个爱瞎折腾的程序猿

sqlserver使用存储过程跟踪SQL

USE [master] GO /****** Object: StoredProcedure [dbo].[sp_perfworkload_trace_s...

2070
来自专栏大内老A

The .NET of Tomorrow

Ed Charbeneau(http://developer.telerik.com/featured/the-net-of-tomorrow/) Exciti...

32010
来自专栏转载gongluck的CSDN博客

cocos2dx 打灰机

#include "GamePlane.h" #include "PlaneSprite.h" #include "BulletNode.h" #include...

5576
来自专栏芋道源码1024

熔断器 Hystrix 源码解析 —— 断路器 HystrixCircuitBreaker

本文主要基于 Hystrix 1.5.X 版本 1. 概述 2. HystrixCircuitBreaker 3. HystrixCircuitBreaker....

5367

扫码关注云+社区