ORA-01578: ORACLE data block corrupted (file # 7, block # 3)


Primary Alert Log shows the Block is corrupted

As such the block is corrupted in Primary this will also corrupt the standby

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Before 11g
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1) In order to not have this , you can do some lagging the database sync by using following parameter, the following setting is for 1 hour, 3600 is in seconds, so the lag will be maintained 1 hr , so immediately when a block is corrupted it will not ship and apply in standby , only after an hour it will, meanwhile if you recover this corrupted block then it will be good.

	archive_lag_target=3600

2) There are also other parameter like, which can be considerd in primary to alert the block check if it corrupted
	db_block_checksum
	db_block_checking

3) If you have backups, recover that block frm rman backup.
	rman> recover datafile 3 block 7;
	Note: you can get the block number from alert or error as above.

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From 11g Onwards
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If the standby is placed in active dataguard, the primary will request standby to get the block from standby and replace in primary , this is automatic you need not to recover manually.

Example can be found in presentations.