Shulou(Shulou.com)06/01 Report--

Oracle cannot work after startup or the database cannot be started

Once the database cannot be started, you first need to check whether the system table is in an uncorrupted state. Generally speaking, if the system table is not damaged, it is easy to recover the data. If the system table has been damaged, then the data recovery staff is required to analyze and check the table structure manually, so that the period of data recovery is relatively long, but the success rate of data recovery is still high. Don't worry about data recovery failure.

2. The ASM storage of Oracle database is damaged.

This failure condition is usually due to partial equipment failure of ASM or database data loss due to ASM reset and other reasons. When this happens, you need to determine whether a large amount of data is written after the failure, and data recovery can usually be performed if you do not continue to write a large amount of data to the database. Therefore, it should also be noted that once this kind of failure occurs in the oracle database, it is necessary to avoid writing data in the device as much as possible, so as not to destroy the original data.

Third, database erroneous deletion, misformatting and loss of other data files

After the data in the Oracle database is lost due to misformatting, deletion and other misoperations, remember not to write data to the database after misoperation. If the data is not written after the data is lost, no matter any operating system, we can fully recover the database through the organization rules of the database. The only disadvantage is that the restorer needs to check the data file name manually.

4. Partial corruption of Oracle data files and corruption of dump files

If the oracle data file is partially damaged, data recovery requires professional data recovery practitioners to extract and reorganize the data before it can be recovered, and the data recovery time is long.

When the Oracle dump file is damaged, the damaged part is removed and the rest can be appended to the data table normally.

Database data recovery recommendations

If the data loss is caused by software, you should try your best to avoid doing too much to the storage and mirror the data as soon as possible after the data loss. If the data loss is caused by a hardware failure, it is necessary to avoid attempts to power up the hardware, so as not to further damage the equipment and increase the difficulty of data recovery.

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