SQL*Plus / as SYSDBA Works Slower in 12c Than in 11gR2 on SE (Doc ID 2384951.1)

Last updated on JANUARY 07, 2025

Applies to:

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

Symptoms

sqlplus / as sysdba works slower in 12c than in 11gr2 On AIX

the same OS calls made by sqlplus command take longer in 12c than in 11g:

11g: 17236118: 89849997: 0.0398: read_sysconfig(0x09001000A01B8578,
0x0000000000000010, 0x0000000000000000, 0x00000000B0000010,
0x00000001100002C0, 0xBADC0FFEE0DDF00D, 0x0000000006010000,
0x09001000A01EE1D0) = 0x0000000000000000
12c: 18088186: 41877541: 0.1610: read_sysconfig(0x09001000A01B8578,
0x0000000000000010, 0x0000000000000000, 0x00000000B0010030,
0x0000000110000788, 0xBADC0FFEE0DDF00D, 0x0000000006010000,
0x09001000A01EE1D0) = 0x0000000000000000

11g:
3211666: 130285621: 0.4328: kwrite(1, " C o n n e c t e d t o"..,
14) = 14
3211666: 130285621: 0.4330: kwrite(1, " O r a c l e D a t a b"..,
58) = 58
12c:
3146022: 53608667: 0.6192: kwrite(1, " C o n n e c t e d t o".., 14)
= 14
3146022: 53608667: 0.6194: kwrite(1, " O r a c l e D a t a b".., 75)
= 75
....................................................

Verified truss -c sqlplus /nolog

and compare between 11.2 and 12.1 environments.