This document is about oracle startup phases and concepts you need to know when you engaged in disaster recovery.

1. ‫ایران‬ ‫اوراکل‬ ‫کاربران‬ ‫ه‬
‫ایران‬ ‫اوراکل‬ ‫کاربران‬ ‫گروه‬
‫خانوادگی‬ ‫نام‬ ‫و‬ ‫نام‬:‫حاجی‬ ‫مسعود‬
‫پور‬ ‫حسن‬
‫ارائه‬ ‫موضوع‬:Oracle startup phases
and concepts
‫تاریخ‬:1396/01/31

2. ‫ایران‬ ‫اوراکل‬ ‫کاربران‬ ‫ه‬
‫دهنده‬‫ارائه‬ ‫درباره‬
‫مدیر‬‫پایگاه‬‫شرکت‬ ‫در‬ ‫داده‬
‫مشاور‬ ‫و‬ ‫انفورماتیک‬ ‫خدمات‬
‫از‬ ‫بیش‬ ‫با‬۵‫در‬ ‫کار‬ ‫سابقه‬ ‫سال‬
‫داده‬ ‫پایگاه‬ ‫زمینه‬‫اوراکل‬
https://ir.linkedin.com/in/masoud-haji-hassan-pour

3. ‫کاربران‬ ‫گروه‬ ‫از‬ ‫سپاس‬ ‫با‬‫ایران‬ ‫اوراکل‬
Oracle startup phases and concepts
‫ارائه‬ ‫موضوع‬

4. ‫ایران‬ ‫اوراکل‬ ‫کاربران‬ ‫ه‬
What is oracle ?
Memory
Structure
Background
Process
Instance Database
Files

5. ‫ایران‬ ‫اوراکل‬ ‫کاربران‬ ‫ه‬
Oracle startup phases
• Shutdown
• Nomount
• Mount
• Open shutdown
nomount
mount
open

6. ‫ایران‬ ‫اوراکل‬ ‫کاربران‬ ‫ه‬
Shutdown stage
At this stage instance is down and only SYS user with OSDBA, OSOPER
privilege can connect to the database.
Users
OSDBA, OSOPER
(dba, oper)
Instance

7. ‫ایران‬ ‫اوراکل‬ ‫کاربران‬ ‫ه‬
Nomount stage
During this phase the database reads the initialization parameters from the
spfile or pfile. If you get an error at this stage, it’s best to check this file
exists, is accessible and contains no errors.
spfile
spfile$ORACLE_SID.ora
pfile
init$ORACLE_SID.ora
Instance
Note: instance could be start without spfile or pfile

8. ‫ایران‬ ‫اوراکل‬ ‫کاربران‬ ‫ه‬
Startup nomount without spfile and pfile
This is called a DUMMY instance which starts with a Memory_target value
(automatic memory management). Generally we use this instance for
restoring spfile from auto backup.
Instance
DUMMY

9. ‫ایران‬ ‫اوراکل‬ ‫کاربران‬ ‫ه‬
Mount stage
During this phase the database checks the control file, this is a small binary
file that records the physical structure of the database.
If you receive errors during the mount phase, then it is best to check the
control file exists. This phase allows for certain DBA activities to take place,
but does not allow general access to the database.
Instance Database
controlfile
+DATA
ModificationRead / Write

10. ‫ایران‬ ‫اوراکل‬ ‫کاربران‬ ‫ه‬
Open stage
During this phase the database tries to start in open mode, ready for all
users to access. It checks the datafiles exist and any errors at this stage you
should check the datafiles.
This phase can be run in restricted or unrestricted mode, depending on
whether you want all users to have access or not.
Instance Database
Read / Write
dba
users

11. ‫ایران‬ ‫اوراکل‬ ‫کاربران‬ ‫ه‬
References
• https://docs.oracle.com/cd/E11882_01/server.112/e25494/start.htm#ADMIN004

12. ‫ایران‬ ‫اوراکل‬ ‫کاربران‬ ‫ه‬
https://ir.linkedin.com/in/masoud-haji-hassan-pour
Masoud Haji Hassan Pour
Mas.Hassanpour@gmail.com
Thanks
for your attention

13. ‫ایران‬ ‫اوراکل‬ ‫کاربران‬ ‫ه‬
‫سبزتان‬ ‫حضور‬ ‫از‬ ‫تشکر‬ ‫با‬