Oracle ORA-600 [4193] ORA-600 [4194] IN SYSTEM ROLLBACK SEGMENT. HOW TO PATCH

Posted by PDSERVICE on Nov 16, 2015 In

Goal

This document presents an option to patch the SYSTEM rollback segment header when errors ORA-600 [4193] / ORA-600 [4194] are

produced in the SYSTEM rollback segment. This situation could be avoiding the database to be opened.

The supported procedure to fix this problem when the SYSTEM rollback segment is affected, is to make a Point In Time Recovery before the

logical inconsistency.

ORA-600 [4193] and ORA-600 [4194] are normally produced by new transactions and it happens when there is a mismatch in the undo

segment header (info in TRN CTL / FREE BLOCK POOL) and the undo segment block . In the case it happens in undo segments other than

SYSTEM the solution is to drop the rollback segment. Here is a procedure to manually fix these errors when the SYSTEM rollback segment is

involved.

Take a backup before applying this procedure.

Using bbed set ktuxc.ktuxcnfb and ktuxc.ktuxcfbp[0..x].ktufbuba to 0 in the SYSTEM rollback segment header. In that way Oracle will use

an empty undo block for the new transaction avoiding the comparison between the undo block segment header and the undo block pointed by

it.

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