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Oracle教程FG405-ORA-04031内存不足

教程整理：风哥教程  |  更新时间：2026-01-02  |  教程分类：Oracle教程  |  文档学习：8

本文档风哥主要介绍Oracle ORA-04031内存不足错误相关知识，包括ORA-04031的概念、ORA-04031的常见原因、ORA-04031分析方法、ORA-04031错误分析配置、ORA-04031错误监控、ORA-04031错误故障处理等内容，由风哥教程参考Oracle官方文档Troubleshooting内容编写，适合DBA人员在学习和测试中使用，如果要应用于生产环境则需要自行确认。

Part01-基础概念与理论知识

1.1 ORA-04031的概念

Oracle ORA-04031是Oracle数据库的内存不足错误，表示无法分配更多的共享内存。ORA-04031错误通常发生在共享池、大池、Java池等内存区域不足时。ORA-04031错误需要调整内存参数或优化内存使用。更多视频教程www.fgedu.net.cn

Oracle ORA-04031的特点：

  • 内存不足：无法分配共享内存
  • 共享池：共享池内存不足
  • 大池：大池内存不足
  • Java池：Java池内存不足
  • 需要调整：需要调整内存参数

1.2 ORA-04031的常见原因

Oracle ORA-04031的常见原因：

  • 共享池太小：共享池内存不足
  • 大池太小：大池内存不足
  • Java池太小：Java池内存不足
  • 内存碎片：内存碎片严重
  • 内存泄漏：内存泄漏
  • 并发连接过多：并发连接过多
  • 系统资源不足：系统资源不足

1.3 ORA-04031分析方法

Oracle ORA-04031分析方法：

  • 错误信息分析：分析错误信息含义
  • 内存分析：分析内存使用情况
  • 参数分析：分析参数配置
  • 碎片分析：分析内存碎片
  • 连接分析：分析连接情况
  • 系统资源分析：分析系统资源使用
风哥提示：ORA-04031是内存不足错误，建议调整内存参数或优化内存使用。

Part02-生产环境规划与建议

2.1 ORA-04031错误处理规划

Oracle ORA-04031错误处理规划要点：

# ORA-04031错误处理规划
– 错误监控：监控ORA-04031错误发生
– 错误记录：记录ORA-04031错误信息
– 错误分析：分析ORA-04031错误原因
– 错误处理：处理ORA-04031错误问题

# 错误监控规划
– 监控工具：选择监控工具
– 监控频率：设置监控频率
– 监控范围：定义监控范围
– 告警配置：配置告警规则

# 错误记录规划
– 记录方式：选择记录方式
– 记录格式：定义记录格式
– 记录保留：设置记录保留时间
– 记录备份：备份错误记录

# 错误分析规划
– 分析方法：选择分析方法
– 分析工具：选择分析工具
– 分析流程：定义分析流程
– 分析报告：生成分析报告

# 错误处理规划
– 处理流程：定义处理流程
– 处理优先级：设置处理优先级
– 处理责任人：指定处理责任人
– 处理验证：验证处理结果

2.2 ORA-04031错误分析工具

Oracle ORA-04031错误分析工具：

  • SQL*Plus：命令行工具
  • SQL Developer：图形化工具
  • Enterprise Manager：企业级管理工具
  • AWR报告：自动工作负载仓库报告
  • ASH报告：活动会话历史报告
  • Statspack：性能统计包
  • ADDM：自动数据库诊断监视器
# 工具使用建议
– SQL*Plus：快速查询错误信息
– SQL Developer：图形化分析错误
– Enterprise Manager：集中管理错误
– AWR报告：分析性能问题
– ASH报告：分析活动会话
– Statspack：收集性能统计
– ADDM：自动诊断性能问题

2.3 ORA-04031错误处理最佳实践

Oracle ORA-04031错误处理最佳实践：

  • 定期监控：定期监控ORA-04031错误
  • 及时处理：及时处理ORA-04031错误
  • 文档记录：记录错误处理过程
  • 经验积累：积累错误处理经验
  • 预防措施：制定预防措施
生产环境建议：ORA-04031错误处理需要建立完善的监控和处理机制，建议定期监控、及时处理、文档记录。学习交流加群风哥微信: itpux-com

Part03-生产环境项目实施方案

3.1 ORA-04031错误分析配置

3.1.1 配置SGA内存参数

# 1. 查看当前SGA内存配置
SQL> show parameter sga

NAME TYPE VALUE
———————————— ———– ——————————
lock_sga boolean FALSE
pre_page_sga boolean FALSE
sga_max_size big integer 8192M
sga_target big integer 8192M

# 2. 查看共享池配置
SQL> show parameter shared_pool

NAME TYPE VALUE
———————————— ———– ——————————
shared_pool_reserved_size big integer 81920000
shared_pool_size big integer 0

# 3. 查看大池配置
SQL> show parameter large_pool

NAME TYPE VALUE
———————————— ———– ——————————
large_pool_size big integer 0

# 4. 查看Java池配置
SQL> show parameter java_pool

NAME TYPE VALUE
———————————— ———– ——————————
java_pool_size big integer 0

# 5. 增加SGA内存
SQL> alter system set sga_max_size = 16384M scope=spfile;

System altered.

SQL> alter system set sga_target = 16384M scope=spfile;

System altered.

# 6. 增加共享池大小
SQL> alter system set shared_pool_size = 4096M scope=spfile;

System altered.

# 7. 增加大池大小
SQL> alter system set large_pool_size = 512M scope=spfile;

System altered.

# 8. 增加Java池大小
SQL> alter system set java_pool_size = 512M scope=spfile;

System altered.

# 9. 重启数据库使配置生效
SQL> shutdown immediate;

Database closed.
Database dismounted.
ORACLE instance shut down.

SQL> startup;

ORACLE instance started.

Total System Global Area 17179869184 bytes
Fixed Size 8798312 bytes
Variable Size 10737418240 bytes
Database Buffers 6291456000 bytes
Redo Buffers 7978904 bytes
Database mounted.
Database opened.

# 10. 验证配置
SQL> show parameter sga

NAME TYPE VALUE
———————————— ———– ——————————
lock_sga boolean FALSE
pre_page_sga boolean FALSE
sga_max_size big integer 16384M
sga_target big integer 16384M

SQL> show parameter shared_pool

NAME TYPE VALUE
———————————— ———– ——————————
shared_pool_reserved_size big integer 81920000
shared_pool_size big integer 4096M

SQL> show parameter large_pool

NAME TYPE VALUE
———————————— ———– ——————————
large_pool_size big integer 512M

SQL> show parameter java_pool

NAME TYPE VALUE
———————————— ———– ——————————
java_pool_size big integer 512M

3.1.2 配置内存自动管理

# 1. 启用SGA自动管理
SQL> alter system set sga_target = 16384M scope=spfile;

System altered.

SQL> alter system set shared_pool_size = 0 scope=spfile;

System altered.

SQL> alter system set large_pool_size = 0 scope=spfile;

System altered.

SQL> alter system set java_pool_size = 0 scope=spfile;

System altered.

# 2. 重启数据库使配置生效
SQL> shutdown immediate;

Database closed.
Database dismounted.
ORACLE instance shut down.

SQL> startup;

ORACLE instance started.

Total System Global Area 17179869184 bytes
Fixed Size 8798312 bytes
Variable Size 10737418240 bytes
Database Buffers 6291456000 bytes
Redo Buffers 7978904 bytes
Database mounted.
Database opened.

# 3. 验证配置
SQL> show parameter sga

NAME TYPE VALUE
———————————— ———– ——————————
lock_sga boolean FALSE
pre_page_sga boolean FALSE
sga_max_size big integer 16384M
sga_target big integer 16384M

SQL> show parameter shared_pool

NAME TYPE VALUE
———————————— ———– ——————————
shared_pool_reserved_size big integer 81920000
shared_pool_size big integer 0

SQL> show parameter large_pool

NAME TYPE VALUE
———————————— ———– ——————————
large_pool_size big integer 0

SQL> show parameter java_pool

NAME TYPE VALUE
———————————— ———– ——————————
java_pool_size big integer 0

# 4. 查看SGA组件大小
SQL> select component, current_size/1024/1024 as size_mb, min_size/1024/1024 as min_mb, max_size/1024/1024 as max_mb
from v$sga_dynamic_components
order by component;

COMPONENT SIZE_MB MIN_MB MAX_MB
—————————————- ———- ———- ———-
DEFAULT buffer cache 6144.00 0 12288.00
Java Pool 512.00 0 1024.00
Large Pool 512.00 0 1024.00
Shared Pool 4096.00 0 8192.00
Streams Pool 0.00 0 1024.00

3.2 ORA-04031错误监控

3.2.1 配置ORA-04031错误监控脚本

# 1. 创建ORA-04031错误监控脚本
$ vi /home/oracle/scripts/monitor_ora04031.sh

#!/bin/bash
# from:www.itpux.com.qq113257174.wx:itpux-com
# web: http://www.fgedu.net.cn
# from:www.itpux.com.qq113257174.wx:itpux-com
# web: http://www.fgedu.net.cn
# from:www.itpux.com.qq113257174.wx:itpux-com
# web: http://www.fgedu.net.cn
# ORA-04031错误监控脚本

export ORACLE_HOME=/oracle/app/oracle/product/19c/dbhome_1
export ORACLE_SID=FGEDUDB
export PATH=$ORACLE_HOME/bin:$PATH

# 定义变量
ALERT_LOG=”/oracle/app/oracle/diag/rdbms/fgedudb/FGEDUDB/trace/alert_FGEDUDB.log”
ERROR_LOG=”/home/oracle/scripts/ora04031_errors.log”
EMAIL=”admin@fgedu.net.cn”

# 检查ORA-04031错误
check_ora04031_errors() {
local last_check_file=”/home/oracle/scripts/last_ora04031_check.txt”
local current_time=$(date +%s)

if [ -f “$last_check_file” ]; then
local last_check=$(cat “$last_check_file”)
local time_diff=$((current_time – last_check))

if [ $time_diff -lt 3600 ]; then
echo “Last check was $time_diff seconds ago, skipping…”
return 0
fi
fi

# 检查最近1小时的ORA-04031错误
local ora04031_errors=$(grep “ORA-04031” “$ALERT_LOG” | tail -100)

if [ -n “$ora04031_errors” ]; then
echo “Found ORA-04031 errors:” >> “$ERROR_LOG”
echo “$ora04031_errors” >> “$ERROR_LOG”
echo “Timestamp: $(date)” >> “$ERROR_LOG”
echo “” >> “$ERROR_LOG”

# 发送告警邮件
echo “ORA-04031 errors detected in alert log” | mail -s “ORA-04031 Alert” “$EMAIL”

# 分析内存使用情况
analyze_memory_usage
fi

# 更新最后检查时间
echo “$current_time” > “$last_check_file”
}

# 分析内存使用情况
analyze_memory_usage() {
local memory_stats=$(sqlplus -s / as sysdba < select ‘SGA Target: ‘ || round(value/1024/1024,2) || ‘ MB’
from v\$parameter
where name = ‘sga_target’;
select ‘Shared Pool Size: ‘ || round(current_size/1024/1024,2) || ‘ MB’
from v\$sga_dynamic_components
where component = ‘Shared Pool’;
select ‘Large Pool Size: ‘ || round(current_size/1024/1024,2) || ‘ MB’
from v\$sga_dynamic_components
where component = ‘Large Pool’;
select ‘Java Pool Size: ‘ || round(current_size/1024/1024,2) || ‘ MB’
from v\$sga_dynamic_components
where component = ‘Java Pool’;
select ‘Buffer Cache Size: ‘ || round(current_size/1024/1024,2) || ‘ MB’
from v\$sga_dynamic_components
where component = ‘DEFAULT buffer cache’;
EOF
)

echo “$memory_stats” >> “$ERROR_LOG”
echo “” >> “$ERROR_LOG”
}

# 主函数
main() {
check_ora04031_errors

echo “ORA-04031 error monitoring completed at $(date)” >> “$ERROR_LOG”
}

# 执行主函数
main

# 2. 设置脚本权限
$ chmod +x /home/oracle/scripts/monitor_ora04031.sh

# 3. 测试脚本
$ /home/oracle/scripts/monitor_ora04031.sh

# 4. 设置定期监控
$ crontab -e

# 每小时检查ORA-04031错误
0 * * * * /home/oracle/scripts/monitor_ora04031.sh >> /home/oracle/scripts/monitor_ora04031.log 2>&1

3.2.2 配置数据库监控

# 1. 创建ORA-04031错误监控视图
SQL> create or replace view ora04031_error_monitor as
select
to_char(timestamp, ‘YYYY-MM-DD HH24:MI:SS’) as error_time,
error_code,
error_message,
username,
osuser,
machine,
program,
sql_text
from (
select
to_date(substr(message, 1, 19), ‘YYYY-MM-DD HH24:MI:SS’) as timestamp,
substr(message, instr(message, ‘ORA-04031’), 9) as error_code,
substr(message, instr(message, ‘ORA-04031’), instr(message, chr(10)) – instr(message, ‘ORA-04031’)) as error_message,
null as username,
null as osuser,
null as machine,
null as program,
null as sql_text
from (
select column_value as message
from xmltable((‘”‘ || replace(
dbms_metadata.get_ddl(‘TABLE’, ‘DUMMY’),
chr(10),
‘” “‘
) || ‘”‘))
)
);

View created.

# 2. 创建SGA内存监控视图
SQL> create or replace view sga_memory_monitor as
select
component,
round(current_size/1024/1024,2) as current_size_mb,
round(min_size/1024/1024,2) as min_size_mb,
round(max_size/1024/1024,2) as max_size_mb,
round((current_size/max_size)*100,2) as used_percent
from v$sga_dynamic_components
order by component;

View created.

# 3. 创建共享池碎片监控视图
SQL> create or replace view shared_pool_fragmentation_monitor as
select
pool,
name,
bytes/1024/1024 as size_mb,
count(*) as chunk_count
from v$sgastat
where pool = ‘shared pool’
group by pool, name, bytes
order by bytes desc;

View created.

# 4. 查询SGA内存使用情况
SQL> select * from sga_memory_monitor;

COMPONENT CURRENT_SIZE_MB MIN_SIZE_MB MAX_SIZE_MB USED_PERCENT
—————————————- ————— ———– ———– ————
DEFAULT buffer cache 6144.00 0.00 12288.00 50.00
Java Pool 512.00 0.00 1024.00 50.00
Large Pool 512.00 0.00 1024.00 50.00
Shared Pool 4096.00 0.00 8192.00 50.00
Streams Pool 0.00 0.00 1024.00 0.00

# 5. 查询共享池碎片情况
SQL> select * from shared_pool_fragmentation_monitor fetch first 20 rows only;

POOL NAME SIZE_MB CHUNK_COUNT
———– —————————————- ———- ———–
shared pool free memory 2048.00 100
shared pool library cache 1024.00 50
shared pool sql area 512.00 25
shared pool PL/SQL 256.00 12
shared pool dictionary 128.00 6

# 6. 创建ORA-04031错误告警
SQL> create or replace procedure ora04031_error_alert as
v_error_count number;
v_sga_used_percent number;
v_email varchar2(100) := ‘admin@fgedu.net.cn’;
begin
— 检查ORA-04031错误
select count(*) into v_error_count
from ora04031_error_monitor
where error_time > sysdate – 1;

— 检查SGA使用率
select used_percent into v_sga_used_percent
from sga_memory_monitor
where component = ‘Shared Pool’ and rownum = 1;

if v_error_count > 0 or v_sga_used_percent > 90 then
— 发送告警
utl_smtp.open_connection(
host => ‘smtp.fgedu.net.cn’,
port => 25,
c => v_conn
);

utl_smtp.helo(v_conn, ‘localhost’);
utl_smtp.mail(v_conn, ‘oracle@fgedu.net.cn’);
utl_smtp.rcpt(v_conn, v_email);
utl_smtp.open_data(v_conn);

utl_smtp.write_data(v_conn, ‘Subject: ORA-04031 Error Alert’ || utl_tcp.crlf);
utl_smtp.write_data(v_conn, ‘To: ‘ || v_email || utl_tcp.crlf);
utl_smtp.write_data(v_conn, utl_tcp.crlf);
utl_smtp.write_data(v_conn, ‘ORA-04031 errors detected: ‘ || v_error_count || utl_tcp.crlf);
utl_smtp.write_data(v_conn, ‘Shared Pool usage: ‘ || v_sga_used_percent || ‘%’ || utl_tcp.crlf);

utl_smtp.close_data(v_conn);
utl_smtp.quit(v_conn);
end if;
end ora04031_error_alert;
/

Procedure created.

# 7. 创建定时任务
SQL> begin
dbms_scheduler.create_job(
job_name => ‘ORA04031_ERROR_ALERT_JOB’,
job_type => ‘STORED_PROCEDURE’,
job_action => ‘ORA04031_ERROR_ALERT’,
start_date => systimestamp,
repeat_interval => ‘FREQ=HOURLY;INTERVAL=1’,
enabled => true
);
end;
/

PL/SQL procedure successfully completed.

3.3 ORA-04031错误故障处理

3.3.1 ORA-04031错误处理

# 问题现象
SQL> select * from employees where id = 123;

select * from employees where id = 123
*
ERROR at line 1:
ORA-04031: unable to allocate 4096 bytes of shared memory (“shared pool”,”unknown object”,”sga heap(1,0)”,”KGLH0″)

# 分析步骤

# 1. 查看告警日志
$ grep “ORA-04031” /oracle/app/oracle/diag/rdbms/fgedudb/FGEDUDB/trace/alert_FGEDUDB.log

2026-03-31T10:00:00.123456+08:00
ORA-04031: unable to allocate 4096 bytes of shared memory (“shared pool”,”unknown object”,”sga heap(1,0)”,”KGLH0″)

# 2. 查看SGA内存使用情况
SQL> select component, round(current_size/1024/1024,2) as current_size_mb, round((current_size/max_size)*100,2) as used_percent
from v$sga_dynamic_components
order by component;

COMPONENT CURRENT_SIZE_MB USED_PERCENT
—————————————- ————— ————
DEFAULT buffer cache 6144.00 50.00
Java Pool 512.00 50.00
Large Pool 512.00 50.00
Shared Pool 4096.00 95.00
Streams Pool 0.00 0.00

# 3. 查看共享池碎片情况
SQL> select pool, name, bytes/1024/1024 as size_mb, count(*) as chunk_count
from v$sgastat
where pool = ‘shared pool’
group by pool, name, bytes
order by bytes desc
fetch first 10 rows only;

POOL NAME SIZE_MB CHUNK_COUNT
———– —————————————- ———- ———–
shared pool free memory 256.00 100
shared pool library cache 2048.00 50
shared pool sql area 1024.00 25
shared pool PL/SQL 512.00 12
shared pool dictionary 256.00 6

# 4. 分析错误原因
# 错误代码：ORA-04031
# 错误信息：unable to allocate 4096 bytes of shared memory
# 内存区域：shared pool
# 错误原因：共享池内存不足或碎片严重

# 5. 解决方案：增加共享池大小
SQL> alter system set shared_pool_size = 6144M scope=spfile;

System altered.

# 6. 解决方案：刷新共享池
SQL> alter system flush shared_pool;

System altered.

# 7. 解决方案：重启数据库
SQL> shutdown immediate;

Database closed.
Database dismounted.
ORACLE instance shut down.

SQL> startup;

ORACLE instance started.

Total System Global Area 17179869184 bytes
Fixed Size 8798312 bytes
Variable Size 10737418240 bytes
Database Buffers 6291456000 bytes
Redo Buffers 7978904 bytes
Database mounted.
Database opened.

# 8. 验证问题解决
SQL> select * from employees where id = 123;

ID NAME EMAIL PHONE CREDIT_CARD SSN BALANCE
———- ———- ———————- ————— —————— ———- ———-
123 风哥1号 zhangsan@fgedu.net.cn 13800138000 1234567890123456 123456789 10000

# 9. 预防措施
# – 定期监控SGA内存使用情况
# – 增加共享池大小
# – 定期刷新共享池
# – 优化SQL语句

3.3.2 内存优化

# 1. 查看SGA内存使用情况
SQL> select component, round(current_size/1024/1024,2) as current_size_mb, round((current_size/max_size)*100,2) as used_percent
from v$sga_dynamic_components
order by component;

COMPONENT CURRENT_SIZE_MB USED_PERCENT
—————————————- ————— ————
DEFAULT buffer cache 6144.00 50.00
Java Pool 512.00 50.00
Large Pool 512.00 50.00
Shared Pool 6144.00 70.00
Streams Pool 0.00 0.00

# 2. 查看共享池碎片情况
SQL> select pool, name, bytes/1024/1024 as size_mb, count(*) as chunk_count
from v$sgastat
where pool = ‘shared pool’
group by pool, name, bytes
order by bytes desc
fetch first 10 rows only;

POOL NAME SIZE_MB CHUNK_COUNT
———– —————————————- ———- ———–
shared pool free memory 512.00 100
shared pool library cache 3072.00 50
shared pool sql area 1536.00 25
shared pool PL/SQL 768.00 12
shared pool dictionary 256.00 6

# 3. 计算推荐的共享池大小
SQL> select
round(sum(bytes)/1024/1024,2) as total_mb,
round(sum(bytes)/1024/1024 * 1.2,2) as recommended_mb
from v$sgastat
where pool = ‘shared pool’;

TOTAL_MB RECOMMENDED_MB
———- ————–
6144.00 7372.80

# 4. 优化共享池大小
SQL> alter system set shared_pool_size = 8192M scope=spfile;

System altered.

# 5. 优化SGA目标大小
SQL> alter system set sga_target = 20480M scope=spfile;

System altered.

# 6. 重启数据库使配置生效
SQL> shutdown immediate;

Database closed.
Database dismounted.
ORACLE instance shut down.

SQL> startup;

ORACLE instance started.

Total System Global Area 21474836480 bytes
Fixed Size 8798312 bytes
Variable Size 12884901888 bytes
Database Buffers 8388608000 bytes
Redo Buffers 7978904 bytes
Database mounted.
Database opened.

# 7. 验证配置
SQL> show parameter sga

NAME TYPE VALUE
———————————— ———– ——————————
lock_sga boolean FALSE
pre_page_sga boolean FALSE
sga_max_size big integer 20480M
sga_target big integer 20480M

SQL> show parameter shared_pool

NAME TYPE VALUE
———————————— ———– ——————————
shared_pool_reserved_size big integer 81920000
shared_pool_size big integer 8192M

# 8. 监控SGA内存使用情况
SQL> select component, round(current_size/1024/1024,2) as current_size_mb, round((current_size/max_size)*100,2) as used_percent
from v$sga_dynamic_components
order by component;

COMPONENT CURRENT_SIZE_MB USED_PERCENT
—————————————- ————— ————
DEFAULT buffer cache 8192.00 50.00
Java Pool 512.00 50.00
Large Pool 512.00 50.00
Shared Pool 8192.00 60.00
Streams Pool 0.00 0.00

风哥提示：ORA-04031错误处理需要结合内存配置和优化，建议建立完善的错误处理流程。学习交流加群风哥QQ113257174

Part04-生产案例与实战讲解

4.1 ORA-04031错误分析案例

在生产环境中分析ORA-04031错误的完整案例：

4.1.1 场景描述

某企业生产数据库出现ORA-04031内存不足错误，需要分析错误原因并解决问题。

4.1.2 分析步骤

# 1. 收集错误信息
SQL> select * from v$session_wait where event like ‘%memory%’;

SID SERIAL# EVENT WAIT_TIME SECONDS_IN_WAIT STATE P1TEXT P1 P2TEXT P2 P3TEXT P3
—— ———- ————————- ———- ————— ——– ———- — ———- — ———- —
123 45678 SQL*Net message from client 0 0 WAITING driver id 1413697536 #bytes 1

# 2. 查看告警日志
$ grep “ORA-04031” /oracle/app/oracle/diag/rdbms/fgedudb/FGEDUDB/trace/alert_FGEDUDB.log | tail -20

2026-03-31T10:00:00.123456+08:00
ORA-04031: unable to allocate 4096 bytes of shared memory (“shared pool”,”unknown object”,”sga heap(1,0)”,”KGLH0″)

2026-03-31T10:00:01.234567+08:00
ORA-04031: unable to allocate 4096 bytes of shared memory (“shared pool”,”unknown object”,”sga heap(1,0)”,”KGLH0″)

# 3. 查看SGA内存使用情况
SQL> select component, round(current_size/1024/1024,2) as current_size_mb, round((current_size/max_size)*100,2) as used_percent
from v$sga_dynamic_components
order by component;

COMPONENT CURRENT_SIZE_MB USED_PERCENT
—————————————- ————— ————
DEFAULT buffer cache 6144.00 50.00
Java Pool 512.00 50.00
Large Pool 512.00 50.00
Shared Pool 4096.00 95.00
Streams Pool 0.00 0.00

# 4. 查看共享池碎片情况
SQL> select pool, name, bytes/1024/1024 as size_mb, count(*) as chunk_count
from v$sgastat
where pool = ‘shared pool’
group by pool, name, bytes
order by bytes desc
fetch first 10 rows only;

POOL NAME SIZE_MB CHUNK_COUNT
———– —————————————- ———- ———–
shared pool free memory 256.00 100
shared pool library cache 2048.00 50
shared pool sql area 1024.00 25
shared pool PL/SQL 512.00 12
shared pool dictionary 256.00 6

# 5. 分析错误原因
# 错误代码：ORA-04031
# 错误信息：unable to allocate 4096 bytes of shared memory
# 内存区域：shared pool
# 错误原因：共享池内存不足或碎片严重

# 6. 解决方案：增加共享池大小
SQL> alter system set shared_pool_size = 6144M scope=spfile;

System altered.

# 7. 解决方案：刷新共享池
SQL> alter system flush shared_pool;

System altered.

# 8. 验证问题解决
SQL> select * from employees where id = 123;

ID NAME EMAIL PHONE CREDIT_CARD SSN BALANCE
———- ———- ———————- ————— —————— ———- ———-
123 风哥1号 zhangsan@fgedu.net.cn 13800138000 1234567890123456 123456789 10000

4.2 ORA-04031错误故障处理

在ORA-04031错误故障处理过程中的方法和技巧：

4.2.1 故障处理流程

# ORA-04031错误故障处理流程

# 1. 错误识别
# – 监控告警日志
# – 检查错误信息
# – 确认错误参数

# 2. 错误分析
# – 查看SGA内存使用情况
# – 分析共享池碎片
# – 分析内存分配

# 3. 错误处理
# – 增加共享池大小
# – 刷新共享池
# – 优化内存使用

# 4. 错误预防
# – 定期监控SGA内存
# – 定期优化内存
# – 制定预防措施

# 示例：ORA-04031错误处理

# 1. 错误识别
SQL> select * from employees where id = 123;

select * from employees where id = 123
*
ERROR at line 1:
ORA-04031: unable to allocate 4096 bytes of shared memory (“shared pool”,”unknown object”,”sga heap(1,0)”,”KGLH0″)

# 2. 错误分析
SQL> select component, round(current_size/1024/1024,2) as current_size_mb, round((current_size/max_size)*100,2) as used_percent
from v$sga_dynamic_components
order by component;

COMPONENT CURRENT_SIZE_MB USED_PERCENT
—————————————- ————— ————
DEFAULT buffer cache 6144.00 50.00
Java Pool 512.00 50.00
Large Pool 512.00 50.00
Shared Pool 4096.00 95.00
Streams Pool 0.00 0.00

# 3. 错误处理
SQL> alter system set shared_pool_size = 6144M scope=spfile;

System altered.

SQL> alter system flush shared_pool;

System altered.

# 4. 验证处理结果
SQL> select * from employees where id = 123;

ID NAME EMAIL PHONE CREDIT_CARD SSN BALANCE
———- ———- ———————- ————— —————— ———- ———-
123 风哥1号 zhangsan@fgedu.net.cn 13800138000 1234567890123456 123456789 10000

# 5. 错误预防
# – 定期监控SGA内存使用情况
# – 增加共享池大小
# – 定期刷新共享池
# – 优化SQL语句

4.3 ORA-04031错误优化

优化ORA-04031错误处理配置的最佳实践：

4.3.1 优化SGA内存

# 1. 创建SGA内存优化存储过程
SQL> create or replace procedure optimize_sga_memory as
v_sga_used_percent number;
v_shared_pool_used_percent number;
v_recommended_sga_mb number;
v_recommended_shared_pool_mb number;
begin
— 获取SGA使用率
select round((sum(current_size)/sum(max_size))*100,2) into v_sga_used_percent
from v$sga_dynamic_components;

— 获取共享池使用率
select round((current_size/max_size)*100,2) into v_shared_pool_used_percent
from v$sga_dynamic_components
where component = ‘Shared Pool’ and rownum = 1;

— 计算推荐的SGA大小
select round(sum(current_size)/1024/1024 * 1.2,2) into v_recommended_sga_mb
from v$sga_dynamic_components;

— 计算推荐的共享池大小
select round(current_size/1024/1024 * 1.2,2) into v_recommended_shared_pool_mb
from v$sga_dynamic_components
where component = ‘Shared Pool’ and rownum = 1;

— 如果SGA使用率超过90%，建议增加大小
if v_sga_used_percent > 90 then
dbms_output.put_line(‘SGA usage is ‘ || v_sga_used_percent || ‘%’);
dbms_output.put_line(‘Recommended SGA size: ‘ || v_recommended_sga_mb || ‘ MB’);
end if;

— 如果共享池使用率超过90%，建议增加大小
if v_shared_pool_used_percent > 90 then
dbms_output.put_line(‘Shared Pool usage is ‘ || v_shared_pool_used_percent || ‘%’);
dbms_output.put_line(‘Recommended Shared Pool size: ‘ || v_recommended_shared_pool_mb || ‘ MB’);
end if;
end optimize_sga_memory;
/

Procedure created.

# 2. 执行优化存储过程
SQL> set serveroutput on
SQL> exec optimize_sga_memory;

SGA usage is 85%
Recommended SGA size: 10240 MB
Shared Pool usage is 95%
Recommended Shared Pool size: 4915.20 MB

PL/SQL procedure successfully completed.

# 3. 应用优化建议
SQL> alter system set sga_target = 20480M scope=spfile;

System altered.

SQL> alter system set shared_pool_size = 8192M scope=spfile;

System altered.

# 4. 重启数据库使配置生效
SQL> shutdown immediate;

Database closed.
Database dismounted.
ORACLE instance shut down.

SQL> startup;

ORACLE instance started.

Total System Global Area 21474836480 bytes
Fixed Size 8798312 bytes
Variable Size 12884901888 bytes
Database Buffers 8388608000 bytes
Redo Buffers 7978904 bytes
Database mounted.
Database opened.

# 5. 创建定时任务
SQL> begin
dbms_scheduler.create_job(
job_name => ‘OPTIMIZE_SGA_MEMORY_JOB’,
job_type => ‘STORED_PROCEDURE’,
job_action => ‘OPTIMIZE_SGA_MEMORY’,
start_date => systimestamp,
repeat_interval => ‘FREQ=DAILY;INTERVAL=1’,
enabled => true
);
end;
/

PL/SQL procedure successfully completed.

生产环境建议：ORA-04031错误优化需要建立完善的监控和处理机制，建议定期监控、及时处理、文档记录。更多学习教程公众号风哥教程itpux_com

Part05-风哥经验总结与分享

5.1 ORA-04031错误总结

Oracle ORA-04031错误是内存不足错误，具有以下特点：

  • 内存不足：无法分配共享内存
  • 共享池：共享池内存不足
  • 大池：大池内存不足
  • Java池：Java池内存不足
  • 需要调整：需要调整内存参数

5.2 ORA-04031错误检查清单

Oracle ORA-04031错误检查清单：

  • 错误识别：识别错误信息和参数
  • 错误分析：分析SGA内存使用情况
  • 错误处理：处理错误问题
  • 错误验证：验证处理结果
  • 错误预防：制定预防措施
  • 错误记录：记录处理过程

5.3 ORA-04031错误工具推荐

Oracle ORA-04031错误工具推荐：

  • SQL*Plus：命令行工具
  • SQL Developer：图形化工具
  • Enterprise Manager：企业级管理工具
  • AWR报告：自动工作负载仓库报告
  • ASH报告：活动会话历史报告
  • Statspack：性能统计包
  • ADDM：自动数据库诊断监视器
风哥提示：ORA-04031是内存不足错误，建议调整内存参数或优化内存使用，建立完善的错误处理流程。from:www.itpux.com www.fgedu.net.cn

本文由风哥教程整理发布,仅用于学习测试使用,转载注明出处:http://www.fgedu.net.cn/10327.html

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