Apparatus and methods for transferring database objects into and out of database systems

• US 20050055351A1
• Filed: 09/05/2003
• Published: 03/10/2005
• Est. Priority Date: 09/05/2003
• Status: Active Grant

• Current Assignee: Oracle International Corporation (Oracle Corporation)
• Original Assignee: Oracle International Corporation (Oracle Corporation)
• Inventors: Fisher, William, Claborn, George H., Barton, Lee B., Stenoish, James
• Granted Patent: US 8,341,120 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 16/23 Updating
• CPC Class Codes: G06F 16/25 Integrating or interfacing systems involving database management systems

Abstract

Techniques for transferring objects between database systems. As implemented in a relational database management system, the techniques employ a data transfer mechanism that operates under control of a master table in the RDBMS that is performing the transfer operation. The master table specifies the kind of transfer operation to be performed, a set of objects to be transferred, operations to be performed on the objects as they are being transferred, and filters for selecting a subset of the objects. During execution of the transfer, the transfer mechanism maintains and updates state in the master table such that queries may be made on the master table to determine the current status of the operation and such that the transfer mechanism may restart the operation after it has been stopped either at the request of a client that is performing the operation or because of an error in the transfer. The master table'"'"'s persistence and the status information it contains permit the client that is performing the operation to detach from the operation without stopping the operation and later again attach to the operation to determine the operation'"'"'s status or to perform operations such as creating new files for the operation or changing the degree of parallelism with which the transfer operation is being performed. Another feature of the transfer mechanism is using an object'"'"'s metadata to determine the most efficient way of transferring the object.

Claims

7-1. The apparatus set forth in claim 1 wherein:

the control database object includes a specification of one or more parameters for the job,

the transfer mechanism transferring the objects in the set as specified by the parameter.

8-2. The apparatus set forth in claim 7 wherein:

the parameter is an estimate only parameter,

the transfer mechanism responding thereto by providing an estimate of the space required for the objects in the set without transferring the objects.

36. A set of files for transferring a set of database objects into a database management system, the set of files comprising:

at lease one file containing the objects belonging to the set thereof; and

a control object in the set thereof that specifies for each object belonging to the set the location of the object in the set of files and an order in which the database management system transfers object during the transfer.

37. The set of files set forth in claim 36 wherein:

the file further includes metadata that defines a type of database objects and one or more database objects that belong to the type defined by the metadata; and

the order determines that the metadata is processed before the database objects that belong to the type defined by the metadata.

38. The set of files set forth in claim 36 further comprising:

a header in each file of the set, the header including

an indication the control object is contained in the file and if so, the location of the control object in the file and

an identifier that identifies the file within the set; and

the control object uses the identifier in specifying the location of the object in the set of files.

39. A method of transferring database objects to a destination, each database object having metadata that defines the database object'"'"'s type and the method comprising the steps of:

obtaining metadata for the object type using the metadata to make a determination of the composition of the objects of the type;

selecting a transfer technique for objects belonging to the type from a plurality thereof according to the determination; and

transferring the objects belonging to the type according to the selected transfer technique.

40. The method of transferring database objects set forth in claim 39 wherein:

in the step of transferring, the objects are transferred in parallel.

41. The method of transferring database objects set forth in claim 40 further comprising the step of:

receiving a value that specifies a degree of parallelism, the objects being transferred in parallel as determined by the degree of parallelism.

42. The method of transferring database objects set forth in claim 40 wherein:

the transfer technique for certain of the objects permits transfer of portions of the contents of the object in parallel; and

in the step of transferring the certain objects, the portions are transferred in parallel.

43. A method of performing a job that transfers a set of database objects into or out of a database management system that includes a transfer mechanism that transfers the database objects under control of a control database object in the database management system that represents the job,

the method comprising the steps of:

defining the job'"'"'s control database object; and

executing the job by causing the transfer mechanism to transfer the set of database objects under control of the job'"'"'s control data base object.

44. The method of performing a job set forth in claim 43 further comprising the step performed in either the defining step or the executing step of:

attaching to the job, attachment permitting at least reading and/or modification of the job'"'"'s control database object.

45. The method of performing a job set forth in claim 44 further comprising the step performed after the step of attaching to the job of:

reading the job'"'"'s control database object to get the job'"'"'s current status.

46. The method of performing a job set forth in claim 44 wherein

the transfer mechanism transfers the data objects in parallel and

the method further comprises the step performed after the step of attaching to the job of:

specifying a degree of parallelism with which the objects may be transferred.

47. The method of performing a job set forth in claim 44 wherein the method further comprises the step performed after the step of attaching to the job of:

starting the step of executing the job.

48. The method of performing a job set forth in claim 44 wherein the method further comprises the step performed after attaching to the job of:

stopping the step of executing the job.

49. The method of performing a job set forth in claim 48 wherein the step of stopping the step of executing the job further comprises the step of:

saving job state in the control database object such that the step of executing the job may be restarted from the job state.

50. The method of performing a job set forth in claim 43 wherein:

the step of defining the job includes the step of creating the job'"'"'s control database object.

51. The method of performing a job set forth in claim 43 wherein:

the step of defining the job includes the step of specifying a source and/or destination for the set of database objects in the job'"'"'s control database object.

52. The method of performing a job set forth in claim 43 wherein:

the step of defining the job includes the step of specifying the set of database objects in the job'"'"'s control database object.

53. The method of performing a job set forth in claim 52 wherein:

the step of defining the job includes the step of specifying a filter in the job'"'"'s control database object, the filter defining a subset of the specified set of database objects as the set of objects to be transferred in the job

54. The method of performing a job set forth in claim 43 wherein:

the step of defining the job includes the step of specifying an operation in the job'"'"'s control database object that is to be performed on one or more objects in the set.

55. The method of performing a job set forth in claim 43 wherein:

the step of defining the job includes the step of defining a parameter for the job in the job'"'"'s control database object for the job.

56. The method of performing a job set forth in claim 43 wherein

the step of executing the job includes the step performed when the step of executing the job must be stopped of:

saving job state in the control database object such that the stopped executing step may be restarted from the job state

57. The method of performing a job set forth in claim 56 wherein the step of executing the job includes the step performed when the step of executing the job has been stopped of:

using the job state to restart the stopped executing step.