120 DBMS_XDB

The DBMS_XDB package supports the following features:

Resource Management subprograms which complement Resource Views
The Access Control List (ACL)-based Security Mechanism
Configuration Session Management
Creation of the XDB username
See Also:
- Oracle XML DB Developer's Guide
- Oracle Database New Features

This chapter contains the following topics:

Using DBMS_XDB
- Overview
- Constants
Summary of DBMS_XDB Subprograms

Using DBMS_XDB

This section contains topics which relate to using the DBMS_XDB package.

Overview
Constants

Overview

The DBMS_XDB package supports the following features:

The Resource Management functionality providesLINK Procedure, EXISTSRESOURCE Function, LOCKRESOURCE Function, GETLOCKTOKEN Procedure, UNLOCKRESOURCE Function, CREATERESOURCE Functions, RENAMERESOURCE Procedure, DELETERESOURCE Procedure, GETRESOID Function, CREATEOIDPATH Function, REBUILDHIERARCHICALINDEX Procedure and CREATEFOLDER Function subprograms which complement Resource Views.
The Access Control List (ACL)-based Security Mechanism can be used with in-hierarchy ACLs stored by the database or in-memory ACLs that may be stored outside the database. Some of these methods can be used for both Oracle resources and arbitrary database objects. Use CHECKPRIVILEGES Function, GETACLDOCUMENT Function, CHANGEPRIVILEGES Function and GETPRIVILEGES Function, LINK Procedure, LINK Procedure, LINK Procedure, LINK Procedure, LINK Procedure, LINK Procedure for Oracle Resources. ACLCHECKPRIVILEGES Function provides access to Oracle's ACL-based Security mechanism without storing objects in the Hierarchy.
Configuration Session Management is supported by CFG_REFRESH Procedure, CFG_GET Function and CFG_UPDATE Procedure. methods.
The XDB username is created during XDB installation. This user owns a set of default tables and packages. GETXDB_TABLESPACE Function and MOVEXDB_TABLESPACE Procedure enable movement of schemas to a specified tablespace, and support the default SYSAUX tablespace introduction

Constants

Table 120-1 Defined Constants for DBMS_XDB

Constant	Type	Value	Description
`DELETE_RESOURCE`	`NUMBER`	1	Deletes a resource; fails if the resource has children.
`DELETE_RECURSIVE`	`NUMBER`	2	Deletes a resource and its children, if any.
`DELETE_FORCE`	`NUMBER`	3	Deletes the resource, even if the object it contains is invalid.
`DELETE_RECURSIVE_FORCE`	`NUMBER`	4	Deletes a resource and its children, if any, even if the object it contains is invalid.

Summary of DBMS_XDB Subprograms

Table 120-2 DBMS_XDB Package Subprograms

Subprogram	Description
ACLCHECKPRIVILEGES Function	Checks access privileges granted to the current user by specified ACL document on a resource whose owner is specified by the 'owner' parameter.
APPENDRESOURCEMETADATA Procedure	Takes in user-defined metadata either as a `REF` to `XMLTYPE` or an `XMLTYPE` and adds it to the desired resource
CFG_GET Function	Retrieves the session's configuration information
CFG_REFRESH Procedure	Refreshes the session's configuration information to the latest configuration
CFG_UPDATE Procedure	Updates the configuration information
CHANGEPRIVILEGES Function	Adds the given ACE to the given resource's ACL
CHECKPRIVILEGES Function	Checks access privileges granted to the current user on the specified resource
CREATEFOLDER Function	Creates a new folder resource in the hierarchy
CREATEOIDPATH Function	Creates a virtual path to the resource based on object ID
CREATERESOURCE Functions	Creates a new resource
DELETERESOURCE Procedure	Deletes a resource from the hierarchy
DELETERESOURCEMETADATA Procedures	Deletes metadata from a resource (can be used for schema-based or nonschema-based metadata)
EXISTSRESOURCE Function	Determines if a resource is the hierarchy, based on its absolute path
GETACLDOCUMENT Function	Retrieves ACL document that protects resource given its path name
GETFTPPORT Function	Gets the value of the current FTP port
GETHTTPPORT Function	Gets the value of the current HTTP port
GETLOCKTOKEN Procedure	Returns that resource's lock token for the current user given a path to a resource
GETPRIVILEGES Function	Gets all privileges granted to the current user on the given resource
GETRESOID Function	Returns the object ID of the resource from its absolute path
GETXDB_TABLESPACE Function	Returns the current tablespace of the XDB (user)
LINK Procedure	Creates a link to an existing resource
LOCKRESOURCE Function	Gets a WebDAV-style lock on that resource given a path to that resource
MOVEXDB_TABLESPACE Procedure	Moves the XDB (user) to the specified tablespace
PURGERESOURCEMETADATA Procedure	Deletes all user metadata from a resource.
REBUILDHIERARCHICALINDEX Procedure	Rebuilds the hierarchical index after import or export operations
RENAMERESOURCE Procedure	Renames the XDB resource
SETACL Procedure	Sets the ACL on the given resource
SETFTPPORT Procedure	Sets the FTP port to a new value
SETHTTPPORT Procedure	Sets the HTTP port to a new value
UPDATERESOURCEMETADATA Procedures	Updates metadata for a resource
UNLOCKRESOURCE Function	Unlocks the resource given a lock token and resource path

ACLCHECKPRIVILEGES Function

This function checks access privileges granted to the current user by specified ACL document by the OWNER of the resource. Returns positive integer if all privileges are granted.

Syntax

DBMS_XDB.ACLCHECKPRIVILEGES(
   acl_path  IN  VARCHAR2,
   owner     IN  VARCHAR2,
   privs     IN  xmltype)
 RETURN PLS_INTEGER;

Parameters

Table 120-3 ACLCHECKPRIVILEGES Function Parameters

Parameter	Description
`acl_path`	Absolute path in the Hierarchy for ACL document
`owner`	Resource owner name; the pseudo user "DAV:owner" is replaced by this user during ACL privilege resolution
`privs`	An `XMLType` instance of the privilege element specifying the requested set of access privileges. See description for CHECKPRIVILEGES Function.

APPENDRESOURCEMETADATA Procedure

This procedure takes in user-defined metadata either as a REF to XMLTYPE or an XMLTYPE and adds it to the desired resource.

Syntax

DBMS_XDB.APPENDRESOURCEMETADATA (
 abspath   IN  VARCHAR2, 
 metadata  IN  XMLTYPE);

DBMS_XDB.APPENDRESOURCEMETADATA (
 abspath   IN  VARCHAR2, 
 metadata  IN  REF SYS.XMLTYPE);

Parameters

Table 120-4 APPENDRESOURCEMETADATA Procedure

Parameter	Description
`abspath`	Absolute path of the resource
`metadata`	Metadata can be schema based or nonschema-based. Schema-based metadata will be stored in its own table.

Usage Notes

In the case in which a REF is passed in, the procedure stores the REF in the resource, and the metadata is stored in a separate table. In this case you are responsible for populating the RESID column for the metadata table. Note that theREF passed in must be unique. In other words, there must not be aREF with the same value in the resource metadata, as this would violate uniqueness of properties. An error will be thrown if users attempt to add a REF that already exists.
In the case where the XMLTYPE is passed in, the data is parsed to determine if it is schema-based or not and stored accordingly.

CFG_GET Function

This function retrieves the session's configuration information as an XMLType instance.

Syntax

DBMS_XDB.CFG_GET 
 RETURN SYS.XMLType;

CFG_REFRESH Procedure

This procedure refreshes the session's configuration information to the latest configuration.

Syntax

DBMS_XDB.CFG_REFRESH;

CFG_UPDATE Procedure

This procedure updates the configuration information and commits the change.

Syntax

DBMS_XDB.CFG_UPDATE(
   xdbconfig   IN  SYS.XMLTYPE);

Parameters

Table 120-5 CFG_UPDATE Procedure Parameters

Parameter	Description
`xdbconfig`	The new configuration data

CHANGEPRIVILEGES Function

This function adds the given ACE to the given resource's ACL.

Syntax

DBMS_XDB.CHANGEPRIVILEGES(
   res_path   IN    VARCHAR2,
   ace        IN    xmltype)
 RETURN PLS_INTEGER;

Parameters

Table 120-6 CHANGEPRIVILEGES Function Parameters

Parameter	Description
`res_path`	Path name of the resource for which privileges need to be changed
`ace`	An `XMLType` instance of the `<ace>` element which specifies the `<principal>`, the operation `<grant>` and the list of privileges

Return Values

A positive integer if the ACL was successfully modified.

Usage Notes

If no ACE with the same principal and the same operation (grant/deny) already exists in the ACL, the new ACE is added at the end of the ACL.

CHECKPRIVILEGES Function

This function checks access privileges granted to the current user on the specified resource.

Syntax

DBMS_XDB.CHECKPRIVILEGES(
   res_path   IN  VARCHAR2,
   privs      IN  xmltype)
 RETURN PLS_INTEGER;

Parameters

Table 120-7 CHECKPRIVILEGES Function Parameters

Parameter	Description
`res_path`	Absolute path in the Hierarchy for resource
`privs`	An `XMLType` instance of the privilege element specifying the requested set of access privileges

Return Values

A positive integer if all requested privileges granted.

CREATEFOLDER Function

This function creates a new folder resource in the hierarchy.

Syntax

DBMS_XDB.CREATEFOLDER(
   path   IN  VARCHAR2)
 RETURN BOOLEAN;

Parameters

Table 120-8 CREATEFOLDER Function Parameters

Parameter	Description
`path`	Path name for the new folder

Return Values

TRUE if operation successful; FALSE, otherwise.

Usage Notes

The given path name's parent folder must already exist in the hierarchy: if '/folder1/folder2' is passed as the path parameter, then '/folder1' must already exist.

CREATEOIDPATH Function

This function creates a virtual path to the resource based on object ID.

Syntax

DBMS_XDB.CREATEOIDPATH(
   oid    IN   RAW)
 RETURN VARCHAR2;

Parameters

Table 120-9 CREATEOIDPATH Function Parameters

Parameter	Description
`oid`	Object ID of the resource

CREATERESOURCE Functions

The functions create a new resource. The description of the overload options precede each version of the syntax

Syntax

Creates a new resource with the given string as its contents:

DBMS_XDB.CREATERESOURCE( 
   path    IN  VARCHAR2,
   data    IN  VARCHAR2)
 RETURN BOOLEAN;

Creates a new resource with the given XMLType data as its contents:

DBMS_XDB.CREATERESOURCE(
   path    IN  VARCHAR2,
   data    IN  SYS.XMLTYPE)
 RETURN BOOLEAN;

Given a REF to an existing XMLType row, creates a resource whose contents point to that row. That row should not already exist inside another resource:

DBMS_XDB.CREATERESOURCE(
   path     IN  VARCHAR2,
   datarow  IN  REF SYS.XMLTYPE)
 RETURN BOOLEAN;

Creates a resource with the given BLOB as its contents, and specifies character set of the source BLOB:

DBMS_XDB.CREATERESOURCE(
   path    IN  VARCHAR2,
   data    IN  BLOB,
   csid    IN  NUMBER :=0)
 RETURN BOOLEAN;

Creates a resource with the given BFILE as its contents, and specifies character set of the source BFILE:

DBMS_XDB.CREATERESOURCE( 
   path    IN  VARCHAR2,
   data    IN  BFILE,
   csid    IN  NUMBER :=0)
 RETURN BOOLEAN;

Creates a resource with the given CLOB as its contents:

DBMS_XDB.CREATERESOURCE(
   path    IN  VARCHAR2,
   data    IN  CLOB)
 RETURN BOOLEAN;

Parameters

Table 120-10 CREATERESOURCE Function Parameters

Parameter	Description
`path`	Path name of the resource to create. The path name's parent folder must already exist in the hierarchy. In other words, if `/foo/bar.txt` is passed in, then folder `/foo` must already exist.
`data`	The new resource's contents. The data will be parsed to check if it contains a schema-based XML document, and the contents will be stored as schema-based in the schema's default table. Otherwise, it will be saved as binary data.
`datarow`	`REF` to an `XMLType` row to be used as the contents
`csid`	Character set id of the document. Must be a valid Oracle id; otherwise returns an error. If a zero CSID is specified then the data is defaulted to the database character set. Otherwise, the encoding of the data is determined as follows: From the path extension, determine the resource's MIME type. If the MIME type is */xml, then the encoding is detected based on Appendix F of the W3C XML 1.0 Reference at http://www.w3.org/TR/2000/REC-xml-20001006; otherwise, it is defaulted to the database character set.

Return Values

TRUE if operation successful; FALSE, otherwise.

DELETERESOURCE Procedure

This procedure deletes a resource from the hierarchy.

Syntax

DBMS_XDB.DELETERESOURCE(
   path          IN      VARCHAR2,
   delete_option IN      PLS_INTEGER);

Parameters

Table 120-11 DELETERESOURCE Procedure Parameters

Parameter	Description
`path`	Path name of the resource to delete
`delete_option`	The option that controls how a a resource is deleted; defined in Table 120-1: `DELETE_RESOURCE` `DELETE_RECURSIVE` `DELETE_FORCE` `DELETE_RECURSIVE_FORCE`

DELETERESOURCEMETADATA Procedures

This procedure takes in a resource by absolute path and removes either the schema-based metadata identified by the REF, or the metadata identified by the namespace and name combination, which can be either schema-based or non-schema based. It will also take an additional (optional) parameter that specifies how to delete it. This parameter is only relevant for schema-based resource metadata that needs to be deleted. For non-schema based metadata, this parameter is ignored.

Syntax

Can be used only or schema-based metadata:

DBMS_XDB.DELETERESOURCEMETADATA (
   abspath        IN  VARCHAR2, 
   metadata       IN  REF SYS.XMLTYPE,
   delete_option  IN  pls_integer := dbms_xdb.DELETE_RESOURCE_METADATA_CASCADE);

Can be used for schema-based or nonschema-based metadata:

DBMS_XDB.DELETERESOURCEMETADATA (
   abspath        IN VARCHAR2,
   metadatans     IN VARCHAR2,
   metadataname   IN VARCHAR2,
   delete_option  IN pls_integer := dbms_xdb.DELETE_RESOURCE_METADATA_CASCADE);

Parameters

Table 120-12 DELETERESOURCEMETADATA Procedure Parameters

Parameter	Description
`abspath`	Absolute path of the resource
`metadata`	`REF` to the piece of metadata (schema based) to be deleted
`mettadatans`	Namespace of the metadata fragment to be removed
`mettadataname`	Local name of the metadata fragment to be removed
`delete_option`	Only applicable for schema-based metadata, this can be one of the following: `DELETE_RES_METADATA_CASCADE` - deletes the corresponding row in the metadata table `DELETE_RES_METADATA_NOCASCADE` - does not delete the row in the metadata table

EXISTSRESOURCE Function

This function indicates if a resource is in the hierarchy. Matches resource by a string that represents its absolute path.

Syntax

DBMS_XDB.EXISTSRESOURCE(
   abspath    IN    VARCHAR2)
 RETURN BOOLEAN;

Parameters

Table 120-13 EXISTSRESOURCE Function Parameters

Parameter	Description
`abspath`	Path name of the resource whose ACL document is required

Return Values

TRUE if the resource is found.

GETACLDOCUMENT Function

This function retrieves ACL document that protects resource given its path name.

Syntax

DBMS_XDB.GETACLDOCUMENT(
   abspath  IN  VARCHAR2)
  RETURN sys.xmltype;

Parameters

Table 120-14 GETACLDOCUMENT Function Parameters

Parameter	Description
`abspath`	Path name of the resource whose ACL document is required

Return Values

The XMLType for ACL document.

GETFTPPORT Function

This procedure gets the value of the current FTP port.

Syntax

DBMS_XDB.GETFTPPORT
 RETURN NUMBER;

GETHTTPPORT Function

This procedure gets the value of the current HTTP port.

Syntax

DBMS_XDB.GETHTTPPORT
 RETURN NUMBER;

GETLOCKTOKEN Procedure

Given a path to a resource, this procedure returns that resource's lock token for the current user.

Syntax

DBMS_XDB.GETLOCKTOKEN(
   path         IN      VARCHAR2,
   locktoken    OUT     VARCHAR2);

Parameters

Table 120-15 GETLOCKTOKEN Procedure Parameters

Parameter	Description
`path`	Path name to the resource
`locktoken`	Logged-in user's lock token for the resource

Usage Notes

The user must have READPROPERTIES privilege on the resource.

GETPRIVILEGES Function

This function gets all privileges granted to the current user on the given resource.

Syntax

DBMS_XDB.GETPRIVILEGES(
   res_path    IN     VARCHAR2)
 RETURN sys.xmltype;

Parameters

Table 120-16 GETPRIVILEGES Function Parameters

Parameter	Description
`res_path`	Absolute path in the hierarchy of the resource

Return Values

An XMLType instance of <privilege> element, which contains the list of all leaf privileges granted on this resource to the current user.

GETRESOID Function

Returns the object ID of the resource from its absolute path.

Syntax

DBMS_XDB.GETRESOID(
   abspath IN VARCHAR2)
RETURN RAW;

Parameters

Table 120-17 GETRESOID Function Parameters

Parameter	Description
`abspath_path`	Absolute path of the resource

Return Values

NULL if the resource is not present.

GETXDB_TABLESPACE Function

This function returns the current tablespace of the XDB (user).

Syntax

DBMS_XDB.GETXDB_TABLESPACE
 RETURN VARCHAR2;

LINK Procedure

This procedure creates a link to an existing resource.

Syntax

DBMS_XDB.LINK(
   srcpath    IN  VARCHAR2,
   linkfolder IN  VARCHAR2,
   linkname   IN  VARCHAR2);

Parameters

Table 120-18 LINK Procedure Parameters

Parameter	Description
`srcpath`	Path name of the resource to which a link is made
`linkfolder`	Folder in which the new link is placed
`linkname`	Name of the new link

LOCKRESOURCE Function

Given a path to a resource, this function gets a WebDAV-style lock on that resource.

Syntax

DBMS_XDB.LOCKRESOURCE(
   path      IN  VARCHAR2,
   depthzero IN  BOOLEAN,
   shared    IN  boolean)
RETURN BOOLEAN;

Parameters

Table 120-19 LOCKRESOURCE Function Parameters

Parameter	Description
`path`	Path name of the resource to lock.
`depthzero`	Currently not supported
`shared`	Passing `TRUE` will obtain a shared write lock

Return Values

TRUE if successful.

Usage Notes

The user must have UPDATE privileges on the resource.

MOVEXDB_TABLESPACE Procedure

This procedure moves the XDB (user) to the specified tablespace.

Syntax

DBMS_XDB.MOVEXDB_TABLESPACE(
   new_tablespace   IN  VARCHAR2);

Parameters

Table 120-20 MOVEXDB_TABLESPACE Procedure Parameters

Parameter	Description
`new_tablespace`	Name of the tablespace where the XDB will be moved

Usage Notes

This operation waits for all concurrent XDB sessions to exit.

PURGERESOURCEMETADATA Procedure

This procedure deletes all user metadata from a resource. Schema-based metadata is removed in cascade mode, rows being deleted from the corresponding metadata tables.

Syntax

DBMS_XDB.PURGERESOURCEMETADATA(  
 abspath  IN  VARCHAR2);

Parameters

Table 120-21 PURGERESOURCEMETADATA Procedure Parameters

Parameter	Description
`abspath`	Absolute path of the resource

REBUILDHIERARCHICALINDEX Procedure

This procedure rebuilds the hierarchical index after import or export operations. This is necessary because data cannot be exported from index tables.

Syntax

DBMS_XDB.REBUILDHIERARCHICALINDEX;

RENAMERESOURCE Procedure

This procedure renames the XDB resource.

Syntax

DBMS_XDB.RENAMERESOURCE(
   srcpath    IN  VARCHAR2,
   destfolder IN  CARCHAR2,
   newname    IN  VARCHAR2);

Parameters

Table 120-22 RENAMERESOURCE Procedure Parameters

Parameter	Description
`srcpath`	Absolute path in the Hierarchy for the source resource destination folder
`destfolder`	Absolute path in the Hierarchy for the destination folder
`newname`	Name of the child in the destination folder

SETACL Procedure

This procedure sets the ACL on the given resource to be the ACL specified by path.

Syntax

DBMS_XDB.SETACL(
   res_path   IN  VARCHAR2,
   acl_path   IN  VARCHAR2);

Parameters

Table 120-23 SETACL Procedure Parameters

Parameter	Description
`res_path`	Absolute path in the Hierarchy for resource
`acl_path`	Absolute path in the Hierarchy for ACL

Usage Notes

The user must have <write-acl> privileges on the resource.

SETFTPPORT Procedure

This procedure sets the FTP port to a new value.

Syntax

DBMS_XDB.SETFTPPORT(
   new_port  IN  NUMBER);

Parameters

Table 120-24 SETFTPPORT Procedure Parameters

Parameter	Description
new_port	Value to which the FTP port will be set

SETHTTPPORT Procedure

This procedure sets the HTTP port to a new value.

Syntax

DBMS_XDB.SETHTTPPORT(
   new_port  IN  NUMBER);

Parameters

Table 120-25 SETHTTPPORT Procedure Parameters

Parameter	Description
new_port	Value to which the HTTP port will be set

UPDATERESOURCEMETADATA Procedures

This procedure updates metadata for a resource. The procedure takes in a resource identified by absolute path and the metadata in it to replace identified by its REF. It replaces that piece of metadata with user-defined metadata which is either in the form of a REF to XMLTYPE or an XMLTYPE.

Syntax

Can be used to update schema-based metadata only. The new metadata must be schema-based:

DBMS_XDB.UPDATERESOURCEMETADATA(
   abspath  IN VARCHAR2,
   oldmetadata    IN   REF SYS.XMLTYPE,
   newmetadata    IN   REF SYS.XMLTYPE)

Can be used to update schema-based metadata only. The new metadata must be schema-based or nonschema-based:

DBMS_XDB.UPDATERESOURCEMETADATA(
   abspath        IN   VARCHAR2,
   oldmetadata    IN   REF SYS.XMLTYPE,
   newmetadata    IN   XMLTYPE);

Can be used for both schema-based and nonschema-based metadata:

DBMS_XDB.UPDATERESOURCEMETADATA(
   abspath        IN   VARCHAR2,
   oldns          IN   VARCHAR2,
   oldname IN VARCHAR,
   newmetadata IN XMLTYPE);

Can be used for both schema-based or nonschema-based metadata. New metadata must be schema-based:

DBMS_XDB.UPDATERESOURCEMETADATA(
   abspath       IN   VARCHAR2,
   oldns         IN   VARCHAR2,
   oldname       IN   VARCHAR,
   newmetadata   IN   REF SYS.XMLTYPE);

Parameters

Table 120-26 UPDATERESOURCEMETADATA Procedure Parameters

Parameter	Description
`abspath`	Absolute path of the resource
`oldmetadata`	`REF` to the old of metadata
`newmetadata`	`REF` to the new, replacement metadata (can be either schema-based or nonschema-based depending on the overload)
`oldns`	Namespace identifying old metadata
`oldname`	Local name identifying old metadata

Usage Notes

In the case of REF, it stores the REF in the resource and the metadata is stored in a separate table. Uniqueness of REFs is enforced. In the case where the XMLTYPE is passed in, data is parsed to determine if it is schema-based or not and is stored accordingly.

UNLOCKRESOURCE Function

This function unlocks the resource given a lock token and a path to the resource.

Syntax

DBMS_XDB.UNLOCKRESOURCE(
   path     IN  VARCHAR2,
   deltoken IN  VARCHAR2)
 RETURN BOOLEAN;

Parameters

Table 120-27 UNLOCKRESOURCE Function Parameters

Parameter	Description
`path`	Path name to the resource
`deltoken`	Lock token to be removed

Return Values

TRUE if operation successful.

Usage Notes

The user must have UPDATE privileges on the resource.