SGA 设置成100G的时候
SQL> show sga Total System Global Area 1.0689E+11 bytes Fixed Size 2265864 bytes Variable Size 1.0469E+10 bytes Database Buffers 9.6368E+10 bytes Redo Buffers 55242752 bytes SQL> show parameter sga NAME TYPE VALUE ------------------------------------ ----------- ------------------------------ lock_sga boolean FALSE pre_page_sga boolean FALSE sga_max_size big integer 100G sga_target big integer 100G [oracle@localhost ~]$ ipcs -m ------ Shared Memory Segments -------- key shmid owner perms bytes nattch status 0x00000000 0 root 644 80 2 0x00000000 32769 root 644 16384 2 0x00000000 65538 root 644 280 2 0x00000000 131075 oracle 640 536870912 38 0x00000000 163844 oracle 640 106837311488 38 0x42e38fd0 196613 oracle 640 2097152 38 0x00000000 262150 oracle 640 67108864 35 0x00000000 294919 oracle 640 1979711488 35 0x8336ca7c 327688 oracle 640 2097152 35
rman的备份速度
RMAN> backup validate tablespace SOE58,SOE59; Starting backup at Jul 17 2020 11:28:19 using channel ORA_DISK_1 channel ORA_DISK_1: starting full datafile backup set channel ORA_DISK_1: specifying datafile(s) in backup set input datafile file number=00061 name=/u01/app/oracle/oradata/orcl/soe58.dbf input datafile file number=00062 name=/u01/app/oracle/oradata/orcl/soe59.dbf channel ORA_DISK_1: backup set complete, elapsed time: 00:02:45 List of Datafiles ================= File Status Marked Corrupt Empty Blocks Blocks Examined High SCN ---- ------ -------------- ------------ --------------- ---------- 61 OK 0 5182564 14168832 41705059 File Name: /u01/app/oracle/oradata/orcl/soe58.dbf Block Type Blocks Failing Blocks Processed ---------- -------------- ---------------- Data 0 5142064 Index 0 3765915 Other 0 78289 File Status Marked Corrupt Empty Blocks Blocks Examined High SCN ---- ------ -------------- ------------ --------------- ---------- 62 OK 0 5157893 14168832 41705226 File Name: /u01/app/oracle/oradata/orcl/soe59.dbf Block Type Blocks Failing Blocks Processed ---------- -------------- ---------------- Data 0 5147359 Index 0 3785272 Other 0 78308 Finished backup at Jul 17 2020 11:31:05
SGA 设置成4G的时候：
SQL> show sga; Total System Global Area 4275781632 bytes Fixed Size 2260088 bytes Variable Size 1476395912 bytes Database Buffers 2734686208 bytes Redo Buffers 62439424 bytes SQL> show parameter sga; NAME TYPE VALUE ------------------------------------ ----------- ------------------------------ lock_sga boolean FALSE pre_page_sga boolean FALSE sga_max_size big integer 4G sga_target big integer 4G SQL> [oracle@localhost ~]$ rman target / Recovery Manager: Release 11.2.0.4.0 - Production on Fri Jul 17 11:34:53 2020 Copyright (c) 1982, 2011, Oracle and/or its affiliates. All rights reserved. connected to target database: ORCL (DBID=1568361654) RMAN> backup validate tablespace SOE60,SOE61; Starting backup at Jul 17 2020 11:39:56 using channel ORA_DISK_1 channel ORA_DISK_1: starting full datafile backup set channel ORA_DISK_1: specifying datafile(s) in backup set input datafile file number=00063 name=/u01/app/oracle/oradata/orcl/soe60.dbf input datafile file number=00064 name=/u01/app/oracle/oradata/orcl/soe61.dbf channel ORA_DISK_1: backup set complete, elapsed time: 00:02:45 List of Datafiles ================= File Status Marked Corrupt Empty Blocks Blocks Examined High SCN ---- ------ -------------- ------------ --------------- ---------- 63 OK 0 5163165 14168832 41705382 File Name: /u01/app/oracle/oradata/orcl/soe60.dbf Block Type Blocks Failing Blocks Processed ---------- -------------- ---------------- Data 0 5142203 Index 0 3785156 Other 0 78308 File Status Marked Corrupt Empty Blocks Blocks Examined High SCN ---- ------ -------------- ------------ --------------- ---------- 64 OK 0 5166446 14168832 41705529 File Name: /u01/app/oracle/oradata/orcl/soe61.dbf Block Type Blocks Failing Blocks Processed ---------- -------------- ---------------- Data 0 5139582 Index 0 3784507 Other 0 78297 Finished backup at Jul 17 2020 11:42:41
oratop监控oracle
Oracle 11g - Primary orcl 11:42:03 up: 500s, 1 ins, 0 sn, 0 us, 4.2G mt, 0% fra, 4 er, 0% db ID %CPU LOAD %DCU AAS ASC ASI ASW ASP AST UST MBPS IOPS IORL LOGR PHYR PHYW %FR PGA TEMP UTPS UCPS SSRT DCTR DWTR %DBT 1 1 1 0 0 0 0 0 0 0 0 1.3k 2 0 22 0 0 30 220M 0 0 1 472u 99 0 100 EVENT (C) TOTAL WAITS TIME(s) AVG_MS PCT WAIT_CLASS RMAN backup & recovery I/O 412449 228 0.6 95 System I/O control file heartbeat 1 4 3999.1 2 Other DB CPU 3 2 os thread startup 72 2 36.0 1 Concurrency ARCH wait for process start 3 3 2 745.6 1 Other ID SID SPID USERNAME PROGRAM SRV SERVICE PGA SQLID/BLOCKER OPN E/T STA STE WAIT_CLASS EVENT/*LATCH W/T 1 2002 64408 SYS rman@loca DED SYS$USE 17M 137s ACT WAI System I/O RMAN backup & recover 246u
从两次测试情况来看速度一模一样！推翻了我之前估计大的SGA对备份有利的推测的假设！
只不过pga用了17m，比较大。
