79 DBMS_REPAIR

Using DBMS_REPAIR

• Overview

• Security Model

• Constants

• Operating Notes

• Exceptions

• Examples

Overview

Security Model

The package is owned by SYS. Execution privilege is not granted to other users.

Constants

The DBMS_REPAIR package defines several enumerated constants that should be used for specifying parameter values. Enumerated constants must be prefixed with the package name. For example, DBMS_REPAIR.TABLE_OBJECT.

Table 79-1 lists the parameters and the enumerated constants.

Operating Notes

The procedure to create the ORPHAN_KEYS_TABLE is similar to the one used to create the REPAIR_TABLE.

CONNECT / AS SYSDBA;
EXEC DBMS_REPAIR.ADMIN_TABLES('ORPHAN_KEYS_TABLE', DBMS_REPAIR.ORPHAN_TABLE,
                               DBMS_REPAIR.CREATE_ACTION);
EXEC DBMS_REPAIR.ADMIN_TABLES('REPAIR_TABLE', DBMS_REPAIR.REPAIR_TABLE,
                               DBMS_REPAIR.CREATE_ACTION);
DESCRIBE ORPHAN_KEYS_TABLE;
DESCRIBE REPAIR_TABLE;
SELECT * FROM ORPHAN_KEYS_TABLE;
SELECT * FROM REPAIR_TABLE;

The DBA would create the repair and orphan keys tables once. Subsequent executions of the CHECK_OBJECT Procedure would add rows into the appropriate table indicating the types of errors found.

The name of the repair and orphan keys tables can be chosen by the user, with the following restriction: the name of the repair table must begin with the 'REPAIR_' prefix, and the name of the orphan keys table must begin with the 'ORPHAN_' prefix. The following code is also legal:

CONNECT / AS SYSDBA;
EXEC DBMS_REPAIR.ADMIN_TABLES('ORPHAN_FOOBAR', DBMS_REPAIR.ORPHAN_TABLE,
                               DBMS_REPAIR.CREATE_ACTION);
EXEC DBMS_REPAIR.ADMIN_TABLES('REPAIR_ABCD', DBMS_REPAIR.REPAIR_TABLE,
                               DBMS_REPAIR.CREATE_ACTION);
DESCRIBE ORPHAN_FOOBAR;
DESCRIBE REPAIR_ABCD;
SELECT * FROM ORPHAN_FOOBAR;
SELECT * FROM REPAIR_ABCD;

When invoking the CHECK_OBJECT Procedure the name of the repair and orphan keys tables that were created should be specified correctly, especially if the default values were not used in the ADMIN_TABLES Procedure or CREATE_ACTION.

Other actions in the ADMIN_TABLES Procedure can be used to purge/delete the REPAIR_TABLE and the ORPHAN_KEYS_TABLE.

Exceptions

Examples

/* Fix the bitmap status for all the blocks in table mytab in schema sys */

EXECUTE DBMS_REPAIR.SEGMENT_FIX_STATUS('SYS', 'MYTAB'); 

/* Mark block number 45, filenumber 1 for table mytab in sys schema as FULL.*/ 

EXECUTE DBMS_REPAIR.SEGMENT_FIX_STATUS('SYS', 'MYTAB', TABLE_OBJECT,1, 45, 1); 

Summary of DBMS_REPAIR Subprograms

ADMIN_TABLES Procedure

This procedure provides administrative functions for the DBMS_REPAIR package repair and orphan key tables.

Syntax

DBMS_REPAIR.ADMIN_TABLES (
   table_name  IN   VARCHAR2,
   table_type  IN   BINARY_INTEGER,
   action      IN   BINARY_INTEGER,
   tablespace  IN   VARCHAR2  DEFAULT NULL);

Parameters

CHECK_OBJECT Procedure

This procedure checks the specified objects and populates the repair table with information about corruptions and repair directives.

Validation consists of block checking all blocks in the object.

Syntax

DBMS_REPAIR.CHECK_OBJECT (
   schema_name       IN  VARCHAR2,
   object_name       IN  VARCHAR2,
   partition_name    IN  VARCHAR2       DEFAULT NULL,
   object_type       IN  BINARY_INTEGER DEFAULT TABLE_OBJECT,
   repair_table_name IN  VARCHAR2       DEFAULT 'REPAIR_TABLE',
   flags             IN  BINARY_INTEGER DEFAULT NULL,
   relative_fno      IN  BINARY_INTEGER DEFAULT NULL,
   block_start       IN  BINARY_INTEGER DEFAULT NULL,
   block_end         IN  BINARY_INTEGER DEFAULT NULL,
   corrupt_count     OUT BINARY_INTEGER);

Parameters

Usage Notes

You may optionally specify a DBA range, partition name, or subpartition name when you want to check a portion of an object.

DUMP_ORPHAN_KEYS Procedure

This procedure reports on index entries that point to rows in corrupt data blocks. For each such index entry encountered, a row is inserted into the specified orphan table.

If the repair table is specified, then any corrupt blocks associated with the base table are handled in addition to all data blocks that are marked software corrupt. Otherwise, only blocks that are marked corrupt are handled.

This information may be useful for rebuilding lost rows in the table and for diagnostic purposes.

Syntax

DBMS_REPAIR.DUMP_ORPHAN_KEYS (
   schema_name       IN  VARCHAR2,
   object_name       IN  VARCHAR2,
   partition_name    IN  VARCHAR2       DEFAULT NULL,
   object_type       IN  BINARY_INTEGER DEFAULT INDEX_OBJECT,
   repair_table_name IN  VARCHAR2       DEFAULT 'REPAIR_TABLE',
   orphan_table_name IN  VARCHAR2       DEFAULT 'ORPHAN_KEYS_TABLE',
   flags             IN  BINARY_INTEGER DEFAULT NULL,
   key_count         OUT BINARY_INTEGER);

Parameters

FIX_CORRUPT_BLOCKS Procedure

This procedure fixes the corrupt blocks in specified objects based on information in the repair table that was previously generated by the CHECK_OBJECT Procedure.

Prior to effecting any change to a block, the block is checked to ensure the block is still corrupt. Corrupt blocks are repaired by marking the block software corrupt. When a repair is effected, the associated row in the repair table is updated with a fix timestamp.

Syntax

DBMS_REPAIR.FIX_CORRUPT_BLOCKS (
   schema_name       IN  VARCHAR2,
   object_name       IN  VARCHAR2,
   partition_name    IN  VARCHAR2       DEFAULT NULL, 
   object_type       IN  BINARY_INTEGER DEFAULT TABLE_OBJECT,
   repair_table_name IN  VARCHAR2       DEFAULT 'REPAIR_TABLE',
   flags             IN  BINARY_INTEGER DEFAULT NULL,
   fix_count         OUT BINARY_INTEGER);

Parameters

ONLINE_INDEX_CLEAN Function

This function performs a manual cleanup of failed or interrupted online index builds or rebuilds. This action is also performed periodically by SMON, regardless of user-initiated cleanup.

This function returns TRUE if all indexes specified were cleaned up and FALSE if one or more indexes could not be cleaned up.

Syntax

DBMS_REPAIR.ONLINE_INDEX_CLEAN (
   object_id      IN BINARY_INTEGER DEFAULT ALL_INDEX_ID,
   wait_for_lock  IN BINARY_INTEGER DEFAULT LOCK_WAIT)
 RETURN BOOLEAN;

Parameters

REBUILD_FREELISTS Procedure

This procedure rebuilds the freelists for the specified object. All free blocks are placed on the master freelist. All other freelists are zeroed.

If the object has multiple freelist groups, then the free blocks are distributed among all freelists, allocating to the different groups in round-robin fashion.

Syntax

DBMS_REPAIR.REBUILD_FREELISTS (
   schema_name    IN VARCHAR2,   
   object_name    IN  VARCHAR2,
   partition_name IN VARCHAR2 DEFAULT NULL,
   object_type    IN BINARY_INTEGER DEFAULT TABLE_OBJECT);

Parameters

SEGMENT_FIX_STATUS Procedure

With this procedure you can fix the corrupted state of a bitmap entry. The procedure either recalculates the state based on the current contents of the corresponding block or sets the state to a specific value.

Syntax

DBMS_REPAIR.SEGMENT_FIX_STATUS (
   segment_owner   IN VARCHAR2,
   segment_name    IN VARCHAR2,
   segment_type    IN BINARY_INTEGER DEFAULT TABLE_OBJECT,
   file_number     IN BINARY_INTEGER DEFAULT NULL,
   block_number    IN BINARY_INTEGER DEFAULT NULL,
   status_value    IN BINARY_INTEGER DEFAULT NULL,
   partition_name  IN VARCHAR2 DEFAULT NULL,);

Parameters

SKIP_CORRUPT_BLOCKS Procedure

This procedure enables or disables the skipping of corrupt blocks during index and table scans of the specified object.

When the object is a table, skip applies to the table and its indexes. When the object is a cluster, it applies to all of the tables in the cluster, and their respective indexes.

Syntax

DBMS_REPAIR.SKIP_CORRUPT_BLOCKS (
   schema_name  IN VARCHAR2,
   object_name  IN VARCHAR2,
   object_type  IN BINARY_INTEGER DEFAULT TABLE_OBJECT,
   flags        IN BINARY_INTEGER DEFAULT SKIP_FLAG);

Parameters