166 DBMS_XDB_VERSION

Oracle XML DB versioning interfaces are found in the DBMS_XBD_VERSION package. Functions and procedures of DBMS_XDB_VERSION help to create a VCR and manage the versions in the version history.

This chapter contains the following topic:

Using DBMS_XDB_VERSION
- Security Model
Summary of DBMS_XDB_VERSION Subprograms

Using DBMS_XDB_VERSION

Security Model

Security Model

Owned by XDB, the DBMS_XDB_VERSION package must be created by SYS or XDB. The EXECUTE privilege is granted to PUBLIC. Subprograms in this package are executed using the privileges of the current user.

Summary of DBMS_XDB_VERSION Subprograms

Table 166-1 DBMS_XDB_VERSION Package Subprograms

Method	Description
CHECKIN Function	Checks in a checked-out VCR and returns the resource id of the newly-created version
CHECKOUT Procedure	Checks out a VCR before updating or deleting it
GETCONTENTSBLOBBYRESID Function	Obtain contents as a `BLOB`
GETCONTENTSCLOBBYRESID Function	Obtain contents as a `CLOB`
GETCONTENTSXMLBYRESID Function	Obtain contents as an `XMLType`
GETPREDECESSORS Function	Retrieves the list of predecessors by path name
GETPREDSBYRESID Function	Retrieves the list of predecessors by resource id
GETRESOURCEBYRESID Function	Obtains the resource as an `XMLType`, given the resource object ID
GETSUCCESSORS Function	Retrieves the list of successors by path name
GETSUCCSBYRESID Function	Retrieves the list of successors by resource id
MAKEVERSIONED Function	Turns a regular resource whose path name is given into a version-controlled resource
UNCHECKOUT Function	Checks in a checked-out resource, returns the resource id of the version before the resource is checked out

CHECKIN Function

This function checks in a checked-out VCR and returns the resource id of the newly-created version.

Syntax

DBMS_XDB_VERSION.CHECKIN(
   pathname VARCHAR2) 
 RETURN DBMS_XDB.resid_type;

Parameters

Table 166-2 CHECKIN Function Parameters

Parameter	Description
`pathname`	The path name of the checked-out resource.

Usage Notes

This is not an auto-commit SQL operation. CHECKIN Function doesn't have to take the same path name that was passed to CHECKOUT Procedure operation. However, the CHECKIN Function path name and the CHECKOUT Procedure path name must be of the same resource for the operations to function correctly. If the resource has been renamed, the new name must be used to CHECKIN Function because the old name is either invalid or is currently bound with a different resource. Exception is raised if the path name does not exist. If the path name has been changed, the new path name must be used to CHECKIN Function the resource.

CHECKOUT Procedure

This procedure checks out a VCR before updating or deleting it.

Syntax

DBMS_XDB_VERSION.Checkout(
   pathname    VARCHAR2);

Parameters

Table 166-3 CHECKOUT Procedure Parameters

Parameter	Description
`pathname`	The path name of the VCR to be checked out.

Usage Notes

This is not an auto-commit SQL operation. Two users of the same workspace cannot CHECKOUT Procedure the same VCR at the same time. If this happens, one user must rollback. As a result, it is good practice to commit the CHECKOUT Procedure operation before updating a resource and avoid loss of the update if the transaction is rolled back. An exception is raised if the given resource is not a VCR, if the VCR is already checked out, if the resource doesn't exist.

GETCONTENTSBLOBBYRESID Function

This function obtain contents as a BLOB.

Syntax

DBMS_XDB_VERSION.GETCONTENTSBLOBYRESID(
   resid      DBMS_XDB.resid_type)
 RETURN BLOB;

Parameters

Table 166-4 GETCONTENTSBLOBYRESID Function Parameters

Parameter	Description
`resid`	The resource id.

GETCONTENTSCLOBBYRESID Function

This function obtains contents as a CLOB.

Syntax

DBMS_XDB_VERSION.GETCONTENTSCLOBYRESID(
   resid     DBMS_XDB.resid_type)
 RETURN CLOB;

Parameters

Table 166-5 GETCONTENTSCLOBYRESID Function Parameters

Parameter	Description
`resid`	The resource id.

GETCONTENTSXMLBYRESID Function

This function obtains contents as an XMLType.

Syntax

DBMS_XDB_VERSION.GETCONTENTSXMLBYRESID(
   resid      DBMS_XDB.resid_type)
 RETURN XMLType;

Parameters

Table 166-6 GETCONTENTSXMLBYRESID Function Parameters

Parameter	Description
`resid`	The resource id.

Return Values

If the contents are not valid XML, returns NULL.

GETPREDECESSORS Function

This function retrieves the list of predecessors by the path name.

Syntax

DBMS_XDB_VERSION.GETPREDECESSORS(
   pathname       VARCHAR2) 
 RETURN resid_list_type;

Parameters

Table 166-7 GETPREDECESSORS Function Parameters

Parameter	Description
`pathname`	The path name of the resource.

Return Values

An exception is raised if pathname is illegal.

GETPREDSBYRESID Function

This function retrieves the list of predecessors by resource id.

Syntax

DBMS_XDB_VERSION.GETPREDSBYRESID(
   resid      resid_type) 
 RETURN resid_list_type;

Parameters

Table 166-8 GETPREDSBYRESID Function Parameters

Parameter	Description
`resid`	The resource id.

Usage Notes

Getting predecessors by RESID is more efficient than by pathname.

Exceptions

An exception is raised if the RESID is illegal.

GETRESOURCEBYRESID Function

This function obtains the resource as an XMLType, given the resource object ID. Because the system does not create a path name for versions, this function is useful for retrieving the resource using its resource id.

Syntax

DBMS_XDB_VERSION.GETRESOURCEBYRESID(
   resid      resid_type) 
 RETURN XMLType;

Parameters

Table 166-9 GETRESOURCEBYRESID Function Parameters

Parameter	Description
`resid`	The resource id.

GETSUCCESSORS Function

Given a version resource or a VCR, this function retrieves the list of the successors of the resource by the path name.

Syntax

DBMS_XDB_VERSION.GETSUCCESSORS( 
   pathname VARCHAR2) 
 RETURN resid_list_type;

Parameters

Table 166-10 GETSUCCESSORS Function Parameters

Parameter	Description
`pathname`	The path name of the resource.

Usage Notes

Getting successors by RESID is more efficient than by pathname.

Exceptions

An exception is raised if the pathname is illegal.

GETSUCCSBYRESID Function

This function retrieves the list of the successors of the resource by resource id using version resource or VCR.

Syntax

DBMS_XDB_VERSION.GETSUCCSBYRESID(
   resid    resid_type) 
  RETURN resid_list_type;

Parameters

Table 166-11 GETSUCCSBYRESID Function Parameters

Parameter	Description
`resid`	The resource id.

Usage Notes

Getting successors by RESID is more efficient than by pathname.

Exceptions

An exception is raised if the pathname is illegal.

MAKEVERSIONED Function

This function turns a regular resource whose path name is given into a version-controlled resource. This new resource is then put under version control. All other path names continue to refer to the original resource.

Syntax

DBMS_XDB_VERSION.MAKEVERSIONED(
   pathname   VARCHAR2) 
 RETURN DBMS_XDB.resid_type;

Parameters

Table 166-12 MAKEVERSIONED Function Parameters

Parameter	Description
`pathname`	The path name of the resource to be put under version control.

Return Values

This function returns the resource ID of the first version, or root, of the VCR.

Usage Notes

If two or more path names are bound with the same resource, a copy of the resource is created, and the given path name is bound with the newly-created copy.

This is not an auto-commit SQL operation. An exception is raised if the resource doesn't exist.

This call is legal for VCR, and neither exception nor warning is raised.
This call is illegal for folder, version history, version resource, and ACL.
No support for Schema-based resources is provided.

UNCHECKOUT Function

This function checks-in a checked-out resource and returns the resource id of the version before the resource is checked out.

Syntax

DBMS_XDB_VERSION.UNCHECKOUT(
   pathname    VARCHAR2) 
 RETURN DBMS_XDB.resid_type;

Parameters

Table 166-13 UNCHECKOUT Function Parameters

Parameter	Description
`pathname`	The path name of the checked-out resource.

Usage Notes

This is not an auto-commit SQL operation. The UNCHECKOUT Function does not have to take the same path name that was passed to the operation by the CHECKOUT Procedure. However, the UNCHECKOUT Function path name and the CHECKOUT Procedure path name must be of the same resource for the operations to function correctly. If the resource has been renamed, the new name must be used to UNCHECKOUT Function, because the old name is either invalid or is currently bound with a different resource. If the path name has been changed, the new path name must be used to UNCHECKOUT Function the resource.

Exceptions

An exception is raised if the path name doesn't exist.