The DBMS_SPACE_ADMIN package provides functionality for locally managed tablespaces.
See Also:
Oracle Database Administrator's Guide for an example and description of usingDBMS_SPACE_ADMIN.This chapter contains the following topics:
Security Model
Constants
Operational Notes
This section contains topics which relate to using the DBMS_SPACE_ADMIN package.
This package runs with SYS privileges; therefore, any user who has privilege to execute the package can manipulate the bitmaps.
Table 135-1 DBMS_SPACE_ADMIN Constants
| Constant | Type | Value | Description |
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Verifies that the space owned by segment is appropriately reflected in the bitmap as used |
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Verifies that the space owned by segment is appropriately reflected in the bitmap as used and that no other segment claims any of this space to be used by it |
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Marks a temporary segment as corrupt whereby facilitating its elimination from the dictionary (without space reclamation) |
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Marks a corrupt temporary segment as valid. It is useful when the corruption in the segment extent map or elsewhere has been resolved and the segment can be dropped normally. |
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Dumps the extent map for a given segment |
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Verifies the bitmap of the tablespace with extent maps of the segments in that tablespace to make sure everything is consistent |
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Marks the block range (extent) as free in the bitmaps |
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Marks the block range (extent) as used in the bitmaps |
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Performs the basic metadata checks |
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Performs deep verification |
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Performs a specific check for the segment |
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Checks high water mark (HWM) |
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Checks integrity among L1, L2 and L3 BMBs (Bit Map Blocks) |
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Checks consistency of segment header with corresponding |
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Checks whether the tablespace bitmaps corresponding to the extent map are marked used |
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Checks whether the L1 BMBs, L2 BMBs, L3 BMBs and data blocks point to the same parent segment |
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Checks whether the bitmap blocks are consistent with the extent map |
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Checks from the datablocks that the bitmap states representing the blocks are consistent |
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Checks whether the tablespace bitmaps are consistent with the extents belonging to that tablespace |
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Performs |
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Performs |
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Dumps only bitmap block summaries |
Before migrating the SYSTEM tablespace, the following conditions must be met. These conditions are enforced by the TABLESPACE_MIGRATE_TO_LOCAL procedure, except for the cold backup.
The database must have a default temporary tablespace that is not SYSTEM.
Dictionary-managed tablespaces cannot have any rollback segments.
A locally managed tablespace must have at least one online rollback segment. If you are using automatic undo management, then an undo tablespace must be online.
All tablespaces—except the tablespace containing the rollback segment or the undo tablespace—must be read-only.
You must have a cold backup of the database.
The system must be in restricted mode.
Table 135-2 DBMS_SPACE_ADMIN Package Subprograms
| Subprogram | Description |
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Verifies segments created in ASSM (Automatic Segment-Space Management) tablespaces |
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Verifies ASSM tablespaces |
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Drops segments from empty tables or table fragments and dependent objects |
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Materializes segments for tables and table fragments with deferred segment creation and their dependent objects |
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Marks the segment corrupt or valid so that appropriate error recovery can be done |
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Drops a segment currently marked corrupt (without reclaiming space) |
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Dumps the segment header and extent maps of a given segment |
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Verifies the consistency of the extent map of the segment |
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Marks the appropriate block range (extent) as free or used in bitmap |
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Fixes the state of the segments in a tablespace in which migration was aborted |
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Migrates a locally managed tablespace to dictionary-managed tablespace |
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Migrates a tablespace from dictionary-managed format to locally managed format |
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Rebuilds the appropriate bitmaps |
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Rebuilds quotas for given tablespace |
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Relocates the bitmaps to the destination specified |
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Verifies that the bitmaps and extent maps for the segments in the tablespace are synchronized |
Given a segment definition, the procedure verifies the basic consistency of the space metadata blocks as well as consistency between space metadata and segment data blocks. This procedure verifies segments created in Automatic Segment Space Management (ASSM) tablespaces.
There is however a difference between basic verification and deep verification:
Basic verification involves consistency checks of space metadata, such as integrity among level 1, level 2, level 3 bitmap blocks, consistency of segment extent map and level 1 bitmap ranges.
Deep verification involves consistency checks between datablocks and space metadata blocks such as whether the datablocks point correctly to the parent level 1 bitmap blocks, and whether the freeness states in the datablocks are consistent with the freeness states of bits in level 1 bitmap blocks corresponding to the datablocks.
DBMS_SPACE_ADMIN.ASSM_SEGMENT_VERIFY ( segment_owner IN VARCHAR2, segment_name IN VARCHAR2, segment_type IN VARCHAR2, partition_name IN VARCHAR2, verify_option IN POSITIVE DEFAULT SEGMENT_VERIFY_BASIC, attrib IN POSITIVE DEFAULT NULL);
Table 135-3 ASSM_SEGMENT_VERIFY Procedure Parameters
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Schema that owns the segment |
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Name of the segment to be verified |
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Segment namespace is one of |
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Name of the partition or subpartition |
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One of the following options:
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When option
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Using this procedure requires SYSDBA privileges.
You can determine the relative file # and header block # (header_relative_file and header_block parameters) by querying DBA_SEGMENTS.
This procedure outputs a dump file named sid_ora_process_ID.trc to the location specified in the USER_DUMP_DEST initialization parameter.
This procedures verifies all the segments created in an ASSM tablespace. The verification for each segment performs basic consistency checks of the space metadata blocks as well as consistency checks between space metadata and segment data blocks.
DBMS_SPACE_ADMIN.ASSM_TABLESPACE_VERIFY ( tablespace_name IN VARCHAR2, ts_option IN POSITIVE, segment_option IN POSITIVE DEFAULT NULL);
Table 135-4 ASSM_TABLESPACE_VERIFY Procedure Parameters
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Name of the tablespace to verify. The tablespace must be an ASSM tablespace. |
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When
The value of |
This procedures drops segments from empty tables or table fragments and dependent objects.
Note:
This functionality is available starting with Oracle Database 11g Release 2 (11.2.0.2).DBMS_SPACE_ADMIN.DROP_EMPTY_SEGMENTS ( schema_name IN VARCHAR2 DEFAULT NULL, table_name IN VARCHAR2 DEFAULT NULL, partition_name IN VARCHAR2 DEFAULT NULL);
Given a schema name, this procedure scans all tables in the schema. For each table, if the table or any of its fragments are found to be empty, and the table satisfies certain criteria (restrictions being the same as those described in "Restrictions on Deferred Segment Creation"), then the empty table fragment and associated index segments are dropped along with the corresponding LOB data and index segments. A subsequent insert creates segments with the same properties.
Optionally:
No schema_name is specified, in which case tables belonging to all schemas are scanned
Both schema_name and table_name are specified to perform the operation on a specified table
All three arguments are supplied, restricting the operation to the partition and its dependent objects
This procedure materializes segments for tables and table fragments with deferred segment creation and their dependent objects.
Note:
This functionality is available starting with Oracle Database 11g Release 2 (11.2.0.2).DBMS_SPACE_ADMIN.MATERIALIZE_DEFERRED_SEGMENTS ( schema_name IN VARCHAR2 DEFAULT NULL, table_name IN VARCHAR2 DEFAULT NULL, partition_name IN VARCHAR2 DEFAULT NULL);
Given a schema name, this procedure scans all tables in the schema. For each table, if the deferred or delayed segment property is set for the table or any of its fragments, then a new segment is created for those fragments and their dependent objects.
Optionally:
No schema_name is specified, in which case tables belonging to all schemas are scanned
Both schema_name and table_name are specified to perform the operation on a specified table
All three arguments are supplied, restricting the operation to the partition and its dependent objects
This procedure marks the segment corrupt or valid so that appropriate error recovery can be done. It cannot be used on the SYSTEM tablespace.
DBMS_SPACE_ADMIN.SEGMENT_CORRUPT ( tablespace_name IN VARCHAR2, header_relative_file IN POSITIVE, header_block IN POSITIVE, corrupt_option IN POSITIVE DEFAULT SEGMENT_MARK_CORRUPT);
Table 135-7 SEGMENT_CORRUPT Procedure Parameters
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Name of tablespace in which segment resides |
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Relative file number of segment header |
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Block number of segment header |
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You can determine the relative file number and block number (header_relative_file and header_block parameter) of the segment header block by querying DBA_SEGMENTS.
The following example marks the segment as corrupt:
EXECUTE DBMS_SPACE_ADMIN.SEGMENT_CORRUPT('USERS', 4, 33, DBMS_SPACE_ADMIN.SEGMENT_MARK_CORRUPT);
Alternately, the next example marks a corrupt segment valid:
EXECUTE DBMS_SPACE_ADMIN.SEGMENT_CORRUPT('USERS', 4, 33, DBMS_SPACE_ADMIN.SEGMENT_MARK_VALID);
This procedure drops a segment currently marked corrupt (without reclaiming space). For this to work, the segment must be marked temporary. To mark a corrupt segment as temporary, issue a DROP command on the segment.
DBMS_SPACE_ADMIN.SEGMENT_DROP_CORRUPT ( tablespace_name IN VARCHAR2, header_relative_file IN POSITIVE, header_block IN POSITIVE);
The space for the segment is not released, and it must be fixed by using the TABLESPACE_FIX_BITMAPS Procedure or the TABLESPACE_REBUILD_BITMAPS Procedure.
The procedure cannot be used on the SYSTEM tablespace.
You can determine the relative file number and block number (header_relative_file and header_block parameter) of the segment header block by querying DBA_SEGMENTS.
This procedure dumps the segment header and bitmap blocks of a specific segment to the location specified in the USER_DUMP_DEST initialization parameter.
DBMS_SPACE_ADMIN.SEGMENT_DUMP ( tablespace_name IN VARCHAR2, header_relative_file IN POSITIVE, header_block IN POSITIVE, dump_option IN POSITIVE DEFAULT SEGMENT_DUMP_EXTENT_MAP);
Table 135-9 SEGMENT_DUMP Procedure Parameters
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Name of tablespace in which segment resides |
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Relative file number of segment header |
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Block number of segment header |
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One of the following options:
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You can produce a slightly abbreviated dump, which includes the segment header and bitmap block summaries, without percent-free states of each block if you pass SEGMENT_DUMP_BITMAP_SUMMARY as the dump_option parameter.
You can determine the relative file number and block number (header_relative_file and header_block parameter) of the segment header block by querying DBA_SEGMENTS.
This procedure checks the consistency of the segment extent map with the tablespace file bitmaps.
DBMS_SPACE_ADMIN.SEGMENT_VERIFY ( tablespace_name IN VARCHAR2, header_relative_file IN POSITIVE, header_block IN POSITIVE, verify_option IN POSITIVE DEFAULT SEGMENT_VERIFY_EXTENTS);
Table 135-10 SEGMENT_VERIFY Procedure Parameters
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Name of tablespace in which segment resides |
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Relative file number of segment header |
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Block number of segment header |
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What kind of check to do: |
Anomalies are output as block range, bitmap-block, bitmap-block-range, anomaly-information, in the trace file for all block ranges found to have incorrect space representation. The kinds of problems which would be reported are free space not considered free, used space considered free, and the same space considered used by multiple segments.
You can determine the relative file number and block number (header_relative_file and header_block parameter) of the segment header block by querying DBA_SEGMENTS.
This procedure marks the appropriate block range (extent) as free or used in bitmap. It cannot be used on the SYSTEM tablespace.
DBMS_SPACE_ADMIN.TABLESPACE_FIX_BITMAPS ( tablespace_name IN VARCHAR2, dbarange_relative_file IN POSITIVE, dbarange_begin_block IN POSITIVE, dbarange_end_block IN POSITIVE, fix_option IN POSITIVE);
Table 135-11 TABLESPACE_FIX_BITMAPS Procedure Parameters
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Name of tablespace |
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Relative file number of block range (extent) |
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Block number of beginning of extent |
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Block number (inclusive) of end of extent |
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One of the following options:
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The following example marks bits for 51 blocks for relative file number 4, beginning at block number 33 and ending at 83, as USED in bitmaps.
EXECUTE DBMS_SPACE_ADMIN.TABLESPACE_FIX_BITMAPS('USERS', 4, 33, 83, DBMS_SPACE_ADMIN.EXTENT_MAKE_USED);
Alternatively, specifying an option of TABLESPACE_EXTENT_MAKE_FREE marks the bits free in bitmaps. The BEGIN and END blocks must be in extent boundary and be extent multiple; otherwise, an error is raised.
This procedure fixes the state of the segments in a tablespace in which migration was aborted. During tablespace migration to or from local, the segments are put in a transient state. If migration is aborted, then the segment states are corrected by SMON when event 10906 is set. A database with segments in such a transient state cannot be downgraded. The procedure can be used to fix the state of such segments.
This procedure migrates a locally managed tablespace to a dictionary-managed tablespace.
The tablespace must be kept online and read/write during migration. Migration of temporary tablespaces and migration of SYSTEM tablespaces are not supported.
This procedure migrates the tablespace from a dictionary-managed format to a locally managed format. Tablespaces migrated to locally managed format are user managed.
DBMS_SPACE_ADMIN.TABLESPACE_MIGRATE_TO_LOCAL ( tablespace_name IN VARCHAR2, unit_size IN POSITIVE DEFAULT NULL, rfno IN POSITIVE DEFAULT NULL);
Table 135-14 TABLESPACE_MIGRATE_TO_LOCAL Procedure Parameters
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Name of the tablespace to be migrated |
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Bitmap unit size (which is the size of the smallest possible chunk of space that can be allocated) in the tablespace specified in number of blocks |
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Relative File Number of the file where the bitmap blocks are placed |
Before you migrate the SYSTEM tablespace, migrate any dictionary-managed tablespaces that you want to use in read/write mode to locally managed. After the SYSTEM tablespace is migrated, you cannot change dictionary-managed tablespaces to read/write.
See Also:
Oracle Database Administrator's GuideThe tablespace must be kept online and read/write during migration. Note that temporary tablespaces cannot be migrated.
Allocation Unit may be specified optionally. The default is calculated by the system based on the highest common divisor of all extents (used or free) for the tablespace. This number is further trimmed based on the MINIMUM EXTENT for the tablespace (5 if MINIMUM EXTENT is not specified). Thus, the calculated value will not be larger than the MINIMUM EXTENT for the tablespace. The last free extent in every file is ignored for GCD calculation. If you specify the unit size, then it must be a factor of the unit_size calculated by the system; otherwise an error message is returned.
The Relative File Number parameter is used to place the bitmaps in a desired file. If space is not found in the file, then an error is issued. The data file specified must be part of the tablespace being migrated. If the dataflow is not specified, then the system chooses a dataflow in which to place the initial bitmap blocks. If space is not found for the initial bitmaps, then an error is raised.
This procedure rebuilds the appropriate bitmaps. If no bitmap block is specified, then it rebuilds all bitmaps for the given tablespace.
The procedure cannot be used on the SYSTEM tablespace.
DBMS_SPACE_ADMIN.TABLESPACE_REBUILD_BITMAPS ( tablespace_name IN VARCHAR2, bitmap_relative_file IN POSITIVE DEFAULT NULL, bitmap_block IN POSITIVE DEFAULT NULL);
This procedure relocates the bitmaps to the destination specified.
DBMS_SPACE_ADMIN.TABLESPACE_RELOCATE_BITMAPS ( tablespace_name IN VARCHAR2, filno IN POSITIVE, blkno IN POSITIVE);
Migration of a tablespace from dictionary-managed to locally managed format could result in the creation of SPACE HEADER segment that contains the bitmap blocks. The SPACE HEADER segment is treated as user data. If you explicitly resize a file at or below the space header segment, then an error is issued. Use the TABLESPACE_RELOCATE_BITMAPS command to move the control information to a different destination and then resize the file.
This procedure cannot be used on the SYSTEM tablespace.
The tablespace must be kept online and read/write during relocation of bitmaps. This can be done only on migrated locally managed tablespaces.
EXECUTE DBMS_SPACE_ADMIN.TABLESPACE_RELOCATE_BITMAPS('TS1', 3, 4);
Moves the bitmaps to file 3, block 4.
Note:
The source and the destination addresses must not overlap. The destination block number is rounded down to the unit boundary. If there is user data in that location, then an error is raised.