Startup and Shutdown

How to Resolve ORA-27125: unable to create shared memory segment

by Ed Chen
February 10, 2023January 12, 2023

ORA-27125 We found error ORA-27125 when we create the second database by Database Configuration Assistant (DBCA). ORA-27125 means that oracle has been bound to the… Read More »

How to Resolve ORA-01507: database not mounted

by Ed Chen
May 16, 2022September 25, 2022

ORA-01507 ORA-01507 means that the command you want to execute cannot be done at NOMOUNT state, you should mount the database from NOMOUNT for further… Read More »

How to Resolve ORA-01033: ORACLE initialization or shutdown in progress

by Ed Chen
November 15, 2021May 24, 2022

ORA-01033 Tried to connect to the database, but it failed with ORA-01033 like the following. SQL> conn hr/hr@orcl ERROR: ORA-01033: ORACLE initialization or shutdown in… Read More »

How to Resolve ORA-01219: database or pluggable database not open: queries allowed on fixed tables or views only

by Ed Chen
October 29, 2021June 8, 2022

ORA-01219 Tried to query a data dictionary, but it failed with ORA-01219. SQL> select * from dba_tablespaces; select * from dba_tablespaces … Read More »

How to Check Oracle Database Startup Time

by Ed Chen
September 17, 2021January 24, 2023

Startup Time Varies To check Oracle database startup or restart time, we have to know the difference between instance startup time and database open time.… Read More »

How to Resolve ORA-09925: Unable to create audit trail file

by Ed Chen
August 20, 2021December 17, 2022

ORA-09925 There're two error scenarios of ORA-09925 in this post: Single-instance Databases RAC Databases Let's see some cases. A. Single-instance Databases Tried to startup a… Read More »

How to Resolve ORA-01149: cannot shutdown - file 1 has online backup set

by Ed Chen
July 7, 2021December 12, 2022

ORA-01149 ORA-01149 means that some data files are in backup mode, so you can't shutdown the database in this moment. SQL> shutdown immediate; ORA-01149: cannot… Read More »

Database States Differentiations in Oracle

by Ed Chen
February 10, 2021January 12, 2023

We have already known that there're 4 states in life cycle of an instance. They are idle, nomount, mount and open. In this post, we… Read More »

How to Resolve "Connected to an idle instance"

by Ed Chen
November 9, 2019December 10, 2022
16 Comments

Connected to an idle instance Actually, Connected to an idle instance is a message rather than an error, it indicates that the database you entered… Read More »

How to Restart Oracle Database

by Ed Chen
September 30, 2019November 21, 2022

In this post, we'll talked about how to restart a database in a efficient way, which includes: Restart a Single-Instance DB Restart a RAC DB… Read More »