Oracle | DBMS

Oracle DBMS_LOBUTIL Version 26ai

General Information

Library Note

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Oracle Database 26ai will be available on generic Linux platforms in January and soon on AIX and Windows

Purpose A container for diagnostic and utility functions and procedures specific to LOBs. Since diagnostic operations are not part of the standard programmatic APIs in DBMS_LOB, they are provided in a separate namespace to avoid clutter. The diagnostic API is also not quite as critical to document for end-users; its main use is for internal developer, QA, and DDR use (especially since it peeks into the internal structure of LOB inodes and lobmaps).

AUTHID DEFINER

Data Types -- dbms_lobutil_inode_t: inode informationCREATE OR REPLACE TYPE dbms_lobutil_inode_t AS OBJECT ( lobid RAW(10), -- lobid flags NUMBER, -- inode flags length NUMBER, -- lob length version NUMBER, -- lob version extents NUMBER, -- #extents in inode lhb NUMBER -- lhb dba); / -- dbms_lobutil_lobmap_t: lobmap information CREATE OR REPLACE TYPE dbms_lobutil_lobmap_t AS OBJECT ( lobid RAW(10), -- lobid eflag NUMBER, -- extent flags rdba NUMBER, -- extent header rdba nblks NUMBER, -- #blocks in extent offset NUMBER, -- offset of extent header length NUMBER -- logical length of extent); -- dbms_lobutil_lobextent_t: extent information CREATE OR REPLACE TYPE dbms_lobutil_lobextent_t AS OBJECT ( rid VARCHAR(32), -- rowid proxy row# NUMBER, -- rownum proxy lobid RAW(10), -- lobid extent# NUMBER, -- extent# [0 .. ] for a lobmap hole VARCHAR(1), -- is the extent a hole? (y/n) cont VARCHAR(1), -- is the extent a superchunk continuation (y/n) over VARCHAR(1), -- is the chunk an overallocation? (y/n) rdba NUMBER, -- rdba of extent start nblks NUMBER, -- #blocks in extent offset NUMBER, -- logical offset of extent start length NUMBER -- logical length of extent); / -- dbms_lobutil_lobextents_t: expanded extent map information CREATE OR REPLACE TYPE dbms_lobutil_lobextents_t AS TABLE OF dbms_lobutil_lobextent_t; /

Dependencies

ANYDATA	DBMS_LOBUTIL_INODE_T	DBMS_LOBUTIL_LOBEXTENT_T
DBMS_LOBUTIL_DEDUPSET_T	DBMS_LOBUTIL_LOBEXTENTS_T	DBMS_LOBUTIL_LOBMAP_T

Documented No

Exceptions

Error Code	Reason
ORA-22275	invalid LOB locator specified

First Available 11.1

Security Model Owned by SYS with EXECUTE granted to PUBLIC

Source {ORACLE_HOME}/rdbms/admin/dbmslobu.sql

Subprograms

COPY_PRIMARY_DEDUP	GETEXTENTS	GETLOBMAP
GETDEDUPSETS	GETINODE	GETPHYSICALLENGTH

COPY_PRIMARY_DEDUP

Copy the primary LOB of a dedup set

Overload 1 dbms_lobutil.copy_primary_dedup( lob_loc IN OUT NOCOPY BLOB, phash IN RAW, fhash IN RAW, scn IN NUMBER DEFAULT 0, par IN NUMBER);

TBD

Overload 2 dbms_lobutil.copy_primary_dedup( lob_loc IN OUT NOCOPY CLOB CHARACTER SET ANY_CS, phash IN RAW, fhash IN RAW, scn IN NUMBER DEFAULT 0, par IN NUMBER);

TBD

GETDEDUPSET

Undocumented deduplication set query
Overload 1 dbms_lobutil.getdedupset(lob_loc IN BLOB) RETURN dbms_lobutil_dedupset_t DETERMINISTIC;

TBD

Overload 2 dbms_lobutil.getdedupset(lob_loc IN CLOB CHARACTER SET ANY_CS) RETURN dbms_lobutil_dedupset_t DETERMINISTIC;

TBD

GETEXTENTS

Undocumented extent expansion dbms_lobutil.getextents(crs IN sys_refcursor) RETURN dbms_lobutil_lobextents_t DETERMINISTIC PIPELINED;

TBD

GETINODE

Undocumented inode query

Overload 1 dbms_lobutil.getinode(lob_loc IN BLOB) RETURN dbms_lobutil_inode_t DETERMINISTIC;

TBD

Overload 2 dbms_lobutil.getinode(lob_loc IN CLOB CHARACTER SET ANY_CS) RETURN dbms_lobutil_inode_t DETERMINISTIC;

TBD

GETLOBMAP

Undocumented LOB map query. Works only with securefiles.

Overload 1

This demo is built to run on the tables created in the SECUREFILES demo dbms_lobutil.getlobmap( lob_loc IN BLOB, n IN NUMBER) RETURN dbms_lobutil_lobmap_t DETERMINISTIC;

set serveroutput on

      

      DECLARE

       bvar BLOB;

       x    dbms_lobutil_lobmap_t;

      BEGIN

        SELECT bcol

        INTO bvar

        FROM reg_tab

        WHERE rownum = 1;

      

        x := dbms_lobutil.getlobmap(bvar, 0);

      END;

      /

      

      DECLARE

       bvar BLOB;

       luty dbms_lobutil_lobmap_t;

      BEGIN

        SELECT bcol

        INTO bvar

        FROM sec_tab

        WHERE rownum = 1;

      

        luty := dbms_lobutil.getlobmap(bvar, 0);

      

        dbms_output.put_line('LOBID: ' || luty.lobid);

        dbms_output.put_line('Extent Flag: ' || luty.eflag);

        dbms_output.put_line('Extent Hdr: ' || luty.rdba);

        dbms_output.put_line('blocks: ' || luty.nblks);

        dbms_output.put_line('offset: ' || luty.offset);

        dbms_output.put_line('length: ' || luty.length);

      END;

      /

Overload 2 dbms_lobutil.getlobmap( lob_loc IN CLOB CHARACTER SET ANY_CS, n IN NUMBER) RETURN dbms_lobutil_lobmap_t DETERMINISTIC;

TBD

GETPHYSICALLENGTH (new 23ai)

Returns the LOB length in either bytes or characters (see below);

Overload 1 dbms_lobutil.getPhysicalLength(lob_loc IN BLOB) RETURN INTEGER DETERMINISTIC;

TBD

Overload 2

We suspect length is measured in bytes, rather than characters, but we are unable to prove it as demonstrated dbms_lobutil.getPhysicalLength(lob_loc IN CLOB) RETURN INTEGER DETERMINISTIC;

SELECT dump(TO_MULTI_BYTE('A'));

      

      DUMP(TO_MULTI_BYTE('A'))

      ------------------------

      Typ=1 Len=3: 239,188,161

      

      

      DECLARE

       c CLOB := TO_MULTI_BYTE('A');

      BEGIN

        dbms_output.put_line(dbms_lobutil.getPhysicalLength(c));

      END;

      /

      *

      ORA-22275: invalid LOB locator specified

Overload 3 dbms_lobutil.getPhysicalLength(lob_loc IN JSON) RETURN INTEGER DETERMINISTIC;

TBD