How to Perform Consistency check of ORACLE database?
Consistency check is used from time to time for a complete confirmation that there is no corruption in a complete database and also to discover any other corruption.
Corruption in Oracle blocks will appear in database with errors in OS, firmware and hardware or software. Corrupted blocks can only be founded when accessing the table in a database. Hence in the current form the errors are not founded and still they are hidden from being discovered. The negative part is these errors are that they make backup to become unusable. These checks requires a lot of time and the best time to run the checkup is when there is less load or off days.
Checking the whole database consumes time but with right processing steps corruption can be detected.
a) Archive logs.
This is an easy way as the database is imported to another database and it also does not harm the original one. The method takes part with the use of RMAN and saving the database. When dumping the new database if shows errors then a corruption has been occurred. But still there might be corruption as no error will be having hidden corruption.
b) Data Files
The first part is to make an Overview of the database, Secondly to make a complete check to find errors in the process. Thirdly is Single object check in which each tables or files are checked.