Data Guard

How to Build Asymmetric Standby Database for Data Guard

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Asymmetric Data Guard Usually we build data guard environments with the symmetric architecture design on primary and standby servers, that is, single-instance to single-instance or RAC to RAC. Practically, we could have downgraded standby servers in hardware specifications. For example, we may use 16 cores per instance on the primary side but use 8 cores […]
RAC

How to Restore 10g RAC Database by a Backup Set

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For 12c RAC database restoration, you may check: How to Restore 12c RAC Database by a Backup Set. Suppose we have recovered 10g CRS and ASM from a fatal crash, but the database is still waiting for our saving. Luckily, we have a backup set of the database, which is a full and consistent database […]
Control File

How to Change Control File Location

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Change Control File Location Here are the steps to change the location of control file: Stop Database Service Copy Control File to New Location Create PFILE from Current SPFILE Modify Control File Location in PFILE Restore SPFILE from Modified PFILE Startup NOMOUNT to Check New Setting Open Database If you’d like to move SPFILE as […]
Administration

How to Move Oracle Database

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Actually, this topic “How to Move Oracle Database” follows my previous post: How to Move ORACLE HOME. But I think it can be used in any moving operations. Generally speaking, this post will include the following subtle topics: How to move spfile How to move control files How to move database files How to move […]
RMAN

How RMAN Restore Database by a Backup Set

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Suppose we have restored the whole OS to the new server including Oracle software and directory structure. Our goal is to restore the database to the target server solely by a backup set for testing purpose. The content of the backup set that we copied from the source server to the target server is listed […]
Backup and Recovery

When Database is Not Consistent

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There are several different kinds of situation when you recover a database with inconsistent states among files. In the following, I have to assume that you can mount the database without question.Data files are consistent, but controlfile is advanced.Do you have all required logs? If you have both archived logs and redo logs, then you […]
Backup and Recovery

When Redo Log Files Are All Missing

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If your redo logs are all missing, then you have to know you will lose some data and no longer to recover it. Now let’s mount the database, I mean you can only startup the database to mount state, and let the control file knows all the situation.SQL> startup mount;ORACLE instance started….Database mounted.Recover the database […]
Control File

When the Controlfile is Missing

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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 must have at least one copy of the controlfile before restoring it. Otherwise, you will have a big trouble. The best practice of the backup strategy against the controlfile is […]
Control File

How to Check Control File Size

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Check Control File Size Control file is a file that have several file attributes including size, but when database is stored upon raw devices, your control files are just symbolic links that represent raw devices. You have no way to check the usage of a raw device. Here are several ways that can check the […]