Ed Chen Logic

When Several Datafiles Are Missing - Restore From Local Backups

by Ed Chen
December 29, 2012December 12, 2022

When several datafiles are accidentally deleted, we can use RMAN to restore and recover the datafiles individually.List the backup we have now.[oracle@primary01 ~]$ rman target… Read More »

When the SPFILE is Missing

by Ed Chen
December 28, 2012December 8, 2021

When you met the following situation, you are about to restore the spfile for your database.SQL> startup open;ORA-01078: failure in processing system parametersORA-01565: error in… Read More »

How to Configure AUTOBACKUP

by Ed Chen
December 27, 2012December 1, 2021

Check AUTOBACKUP ON The default configuration of AUTOBACKUP is ON in RMAN. For those databases which are disabled, we can enable it like this: RMAN>… Read More »

How RMAN Backup Controlfile

by Ed Chen
December 27, 2012October 4, 2022

Backup Controlfile Since the controlfile is a very busy file on reading and writing when your database is open, you can't copy the file directly… Read More »

How to Restore Controlfile

by Ed Chen
December 27, 2012December 8, 2021

When the controlfile is missing, the database can't mount the controlfile, you need to restore the controlfile before going further. But first of all, you… Read More »

How to Make Data Pump Faster

by Ed Chen
December 26, 2012December 11, 2022

Data Pump is a more flexible and powerful utility than legacy exp or imp, which has no NLS_LANG conversion issue bothering us, so we like… Read More »

How to Compare Two Databases After Migration (3/3) - Comparing Row Counts by Actually Counting

by Ed Chen
December 25, 2012October 16, 2019

How to Compare Two Databases After Migration (2/3) - Comparing Row Counts by Leveraging StatisticsWe have introduced a sample stored procedure to compare tables from… Read More »

How to Compare Two Databases After Migration (2/3) - Comparing Row Counts by Leveraging Statistics

by Ed Chen
December 24, 2012October 16, 2019

How to Compare Two Databases After Migration (1/3) - Comparing Initialization ParametersAfter a data migration, you might want to compare the number of rows of… Read More »

How to Compare Two Databases After Migration (1/3) - Comparing Initialization Parameters

by Ed Chen
December 23, 2012October 16, 2019

Go Back to Overview - How to Compare Two Databases After Migration (0/3) - An OverviewThe initialization parameters of a standby database might deviate from… Read More »

How to Compare Two Databases After Migration (0/3) - An Overview

by Ed Chen
December 22, 2012December 28, 2020

After migrating a database, you might want to know the differences between source and target database, if there's any loss, you can take actions right… Read More »