oracle数据库内存调整之增加内存

注：本文来源：小颜Kevin   《oracle数据库内存调整之增加内存》

模拟操作系统内存从2G增加为8G后，调整数据库内存参数，示例中参数不作为实际生产环境参考，因为因需所取，调整参数需要根据数据库相应调整，避免小牛拉大车，大牛拉小车的现象。

查看原始配置数据

  1 [[email protected] ~]$ sqlplus / as sysdba
  2
  3 SQL*Plus: Release 11.2.0.4.0 Production on Sat Jan 7 18:42:30 2017
  4
  5 Copyright (c) 1982, 2013, Oracle.  All rights reserved.
  6
  7 Connected to:
  8 Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 - 64bit Production
  9 With the Partitioning, Real Application Clusters, Automatic Storage Management, OLAP,
 10 Data Mining and Real Application Testing options
 11
 12 SQL> show parameter sga;
 13
 14 NAME                                 TYPE        VALUE
 15 ------------------------------------ ----------- ------------------------------
 16 lock_sga                             boolean     FALSE
 17 pre_page_sga                         boolean     FALSE
 18 sga_max_size                         big integer 700M
 19 sga_target                           big integer 0
 20 SQL> show parameter pga
 21
 22 NAME                                 TYPE        VALUE
 23 ------------------------------------ ----------- ------------------------------
 24 pga_aggregate_target                 big integer 0
 25 SQL> show parameter mem
 26
 27 NAME                                 TYPE        VALUE
 28 ------------------------------------ ----------- ------------------------------
 29 hi_shared_memory_address             integer     0
 30 memory_max_target                    big integer 1G
 31 memory_target                        big integer 1G
 32 shared_memory_address                integer     0
 33 SQL> ho cat /etc/sysctl.conf | grep shmmax
 34 # oracle-rdbms-server-11gR2-preinstall setting for kernel.shmmax is 4398046511104 on x86_64
 35 # oracle-rdbms-server-11gR2-preinstall setting for kernel.shmmax is 4294967295 on i386
 36 kernel.shmmax = 4398046511104
 37 kernel.shmmax = 4294967295
 38
 39 SQL> select 4294967295/1024/1024 from dual;
 40
 41 4294967295/1024/1024
 42 --------------------
 43                 4096
 44
 45 SQL> select 8*1024*1024*1024 from dual;
 46
 47 8*1024*1024*1024
 48 ----------------
 49       8589934592
 50
 51 SQL> exit
 52 [[email protected] ~]$ exit
 53 [[email protected] ~]# /oracle/app/grid/11.2.0.3/bin/crsctl stop crs
 54 [[email protected] ~]# halt
 55 关机后增加物理内存，开机后修改参数
 56 [[email protected] ~]# echo "kernel.shmmax = 8589934592" >> /etc/sysctl.conf
 57 [[email protected] ~]# sysctl -p
 58 [[email protected] ~]# df -ThP
 59 Filesystem    Type    Size  Used Avail Use% Mounted on
 60 /dev/sda5     ext4     87G   20G   63G  24% /
 61 tmpfs        tmpfs    4.0G     0  4.0G   0% /dev/shm
 62 /dev/sda1     ext4    504M   61M  418M  13% /boot
 63 /dev/sda2     ext4    7.7G  146M  7.2G   2% /tmp
 64 [[email protected] ~]# grep tmpfs /etc/fstab
 65 tmpfs                   /dev/shm                tmpfs   defaults        0 0
 66 [[email protected] ~]# vim /etc/fstab
 67 [[email protected] ~]# grep tmpfs /etc/fstab
 68 tmpfs                   /dev/shm                tmpfs   defaults,size=8192m        0 0
 69 [[email protected] ~]# mount -o remount tmpfs
 70 [[email protected] ~]# df -ThP
 71 Filesystem    Type    Size  Used Avail Use% Mounted on
 72 /dev/sda5     ext4     87G   20G   63G  24% /
 73 tmpfs        tmpfs    8.0G  116M  7.9G   2% /dev/shm
 74 /dev/sda1     ext4    504M   61M  418M  13% /boot
 75 /dev/sda2     ext4    7.7G  146M  7.2G   2% /tmp
 76 调整
 77 SQL> select 7*1024 from dual;
 78
 79     7*1024
 80 ----------
 81       7168
 82
 83 SQL> select 8*0.56*1024 from dual;
 84
 85 8*0.56*4.48*1024
 86 ----------------
 87          4587.52
 88
 89 SQL> alter system set memory_max_target=7168M scope=spfile;
 90
 91 System altered.
 92
 93 SQL> alter system set memory_target=7168M scope=spfile;
 94
 95 System altered.
 96
 97 SQL> alter system set sga_max_size=4587M scope=spfile;
 98
 99 System altered.
100
101 SQL> alter system set sga_target=4587M scope=spfile;
102
103 System altered.
104
105 SQL> shutdown immediate
106 Database closed.
107 Database dismounted.
108 ORACLE instance shut down.
109 SQL> startup
110 ORACLE instance started.
111
112 Total System Global Area    4793552896 bytes
113 Fixed Size                     2261328 bytes
114 Variable Size               1124077232 bytes
115 Database Buffers            3657433088 bytes
116 Redo Buffers                   9781248 bytes
117 Database mounted.
118 Database opened.
119 SQL> show parameter sga
120
121 NAME                                 TYPE        VALUE
122 ------------------------------------ ----------- ------------------------------
123 lock_sga                             boolean     FALSE
124 pre_page_sga                         boolean     FALSE
125 sga_max_size                         big integer 4592M
126 sga_target                           big integer 4592M
127 SQL> show parameter pga
128
129 NAME                                 TYPE        VALUE
130 ------------------------------------ ----------- ------------------------------
131 pga_aggregate_target                 big integer 0
132 SQL> show parameter mem
133
134 NAME                                 TYPE        VALUE
135 ------------------------------------ ----------- ------------------------------
136 hi_shared_memory_address             integer     0
137 memory_max_target                    big integer 7G
138 memory_target                        big integer 7G
139 shared_memory_address                integer     0
140
141 SQL> exit