Original Post can be viewed at Physical Corruption: ORA-1578 part 3

Recently we encountered a block corruption issue in 10g database on Linux x86 64 bit and using ASM for storing database files. Saurabh had earlier written articles on ora-1578. http://askdba.org/weblog/2008/04/physical-corruption-ora-1578-part-1/ http://askdba.org/weblog/2008/05/physical-corruption-ora-1578-part-2/ It was first time I was working on a corruption issue, so I followed above notes and found them quite useful. Good thing about [...]

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Original Post can be viewed at Recovering from ORA-1578 ORA-8103 (Logical Corruption)

1. For ORA-1578: There are two ways in which we can extract the data from a corrupted table: a) Using DBMS_REPAIR.SKIP_CORRUPT_BLOCKS b) Using Event 10231 a) Connect as sysdba user: execute DBMS_REPAIR.SKIP_CORRUPT_BLOCKS(‘<schema_name>’,'<table_name>’); Put the schema name and the table name of the corrupted table. Then issue the following command to craete a new table from [...]

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Original Post can be viewed at Physical Corruption: ORA-1578 PART-2

Recovering from physical corruption: 1. Using BMR when RMAN backups are available When small set of blocks are corrupted, Block Media Recovery (BMR) can be used as a recovery technique. The advantage of BMR is that it can be performed without taking the datafiles offline but the block undergoing BMR is not accessible to users. [...]

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Original Post can be viewed at Physical Corruption: ORA-1578 -Part 1

ORA-1578 is indication of physical block corruption. Oracle computes an internal checksum before fetching the block from disk, when it is about to fetch the block it reads the block header and compare the checksum stored in it. If the checksum mismatches we get ora-1578 error.It indicates that a block is corrupted at hardware level [...]

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