sqlplus /as sysdba 这条命令啥意思?

Posted 2023-04-13

参考技术A 他的意思是，在本机以超级管理员登陆
sysdba就是以超级管理员身份 参考技术B 以数据库管理员(Data Base Administrator)的身份登录数据库

sqlplus / as sysdba登录很慢的问题

Slow SYSDBA OS authentication (Doc ID 2225093.1)

APPLIES TO:

Oracle Database Cloud Schema Service - Version N/A and later
Oracle Database Exadata Express Cloud Service - Version N/A and later
Oracle Database Exadata Cloud Machine - Version N/A and later
Oracle Cloud Infrastructure - Database Service - Version N/A and later
Oracle Database Backup Service - Version N/A and later
Information in this document applies to any platform.

SYMPTOMS

 SYSDBA OS authentication takes almost 16 seconds ( sqlplus / as sysdba )
the strace shows there is a read delay for AUTH_VERSION_S

03:33:03 read(7, "", 4096) = 0
03:33:03 close(7) = 0
03:33:03 munmap(0x7f3b433cb000, 4096) = 0
03:33:03 write(8,
"\\4z\\0\\0\\6\\0\\0\\0\\0\\0\\3s\\3\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0!\\0\\0\\0\\376\\377\\377"...,
1146) = 1146
03:33:03 read(9,
"\\4\\250\\0\\0\\6\\0\\0\\0\\0\\0\\10\\31\\0\\23\\0\\0\\0\\23AUTH_VERSION_S"..., 8208) = 1192
03:33:18
open("/u01/app/oracle/product/11.2.0.4/dbhome_1/rdbms/mesg/oraus.msb",
O_RDONLY) = 7 -------------------------------------->>> 15
secs
03:33:18 fcntl(7, F_SETFD, FD_CLOEXEC) = 0
03:33:18 lseek(7, 0, SEEK_SET) = 0
03:33:18 read(7,
"\\25\\23\\"\\1\\23\\3\\t\\t\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0"...,
256) = 256
03:33:18 lseek(7, 512, SEEK_SET) = 512
03:33:18 read(7,
"f\\31\\2603fJ>h\\265z\\342\\207C\\226]\\310m\\374\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0"...,
512) = 512
03:33:18 lseek(7, 1024, SEEK_SET) = 1024

 

CAUSE

 excessively large number of audit files under /u01/app/oracle/admin/adump (created due to excessive SYSDBA connections) causing all the local connections to this Database to hang.

SOLUTION

 Clear the old OS audit files under /u01/app/oracle/admin/adump