Ed Chen Logic - To Make My Logic More Logical

How to Resolve ORA-01624: log needed for crash recovery of instance

by Ed Chen
February 27, 2021January 28, 2021

ORA-01624 ORA-01624 means that the redo log group that you want to operate with is needed for recovery once the database startup after a crash.… Read More »

How to Modify VARCHAR2 into CLOB of a Column

by Ed Chen
February 24, 2021February 24, 2021

Major Data Types There're several major data types built in Oracle. Character Numeric Datetime LONG RAW LOB (Large Object) In each major data types, minor… Read More »

How RMAN Duplex Backup Copies

by Ed Chen
February 20, 2021January 7, 2021

After knowing how to change the backup location in different scenarios, let's see a more advance topic about making backup copies in RMAN. By default,… Read More »

How RMAN Set Backup Location

by Ed Chen
February 17, 2021January 28, 2021

By default, all backup pieces of RMAN go to Fast Recovery Area (FRA), but we can change it. In RMAN, we can set different backup… Read More »

How to Remove MGMT Database

by Ed Chen
February 13, 2021December 24, 2020

Some DBA may consider to remove MGMT database because of resource consuming. I myself found that MGMT database is error-prone when we apply patches on… Read More »

How to Relocate MGMT Database

by Ed Chen
February 13, 2021January 9, 2021

The Management Database (MGMTDB), or say Grid Infrastructure Management Repository (GIMR) is a database which collects real time performance data of each node. It can… Read More »

How to Tell What State of Database

by Ed Chen
February 10, 2021February 3, 2021

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 Change Both DB_NAME and DB_UNIQUE_NAME of a RAC Database

by Ed Chen
February 6, 2021January 11, 2021

We plan to do the following items in order to change both DB_NAME and DB_UNIQUE_NAME of a RAC database. Database Level: Change DB_NAME of a… Read More »

How to Change DB_UNIQUE_NAME of a RAC Database

by Ed Chen
February 3, 2021January 24, 2021

In previous post, we have talked about how to change DB_NAME of a RAC database. In this post, we will talk about how to change… Read More »

How to Change DB_NAME of a RAC Database

by Ed Chen
January 30, 2021February 1, 2021

In previous post, we have talked about how to change DBID of a RAC database. In this post, we will talk about how to change… Read More »