Method and apparatus for identifying files used to restore a file

• US 6,073,128 A
• Filed: 10/31/1997
• Issued: 06/06/2000
• Est. Priority Date: 10/31/1997
• Status: Expired due to Term

• Current Assignee: Oracle International Corporation (Oracle Corporation)
• Original Assignee: Oracle Corporation
• Inventors: Wertheimer, Steven, Bridge, William, Pongracz, Gregory
• Primary Examiner(s): Fetting, Anton W.
• Assistant Examiner(s): Corrielus, Jean M
• Application Number:
  US08/962,087
• Time in Patent Office: 949 Days
• Field of Search: 707/102, 707/3, 707/204, 707/201, 707/10, 395/200, 714/6
• US Class Current: 707/640
• CPC Class Codes: G06F 11/1469 Backup restoration techniques
• CPC Class Codes: Y10S 707/99933 Query processing, i.e. searching
• CPC Class Codes: Y10S 707/99943 Generating database or data structure, e.g. via user interface
• CPC Class Codes: Y10S 707/99952 Coherency, e.g. same view to multiple users
• CPC Class Codes: Y10S 707/99953 Recoverability

Abstract

A method and apparatus identifies backup files that will restore a file in a transactional system. A reset stamp and filename is used to identify all backup files of the file having the filename since the file was last restored. A smaller number of files necessary to restore the file are selected from these backup files by sorting the list of files and selecting certain files in sort order. If necessary, earlier reset stamps are identified and more files are identified and selected, until a file is selected that contains a full backup or datafile copy of the file. For the backup files selected, information such as the location of the file is stored in the order in which the backup files are selected. The information, such as the location of each file selected, is provided in an order that is the reverse of the order in which the files were selected so that the oldest file is listed first. The files may be restored in the order provided.

Claims

1. An apparatus for identifying at an output a plurality of files to restore, comprising:

a file list builder module having a first input operatively coupled for receiving a plurality of sets of information corresponding to backup files, a second input operatively coupled for receiving at least one first identifier corresponding to a plurality of files comprising a most recent backup file, the file list builder module for automatically identifying at an output at least one of the sets of information corresponding to the at least one first identifier; and

a file list scanner module having an input coupled to the file list builder module output, the file list scanner module for identifying and providing at a first output coupled to the apparatus output less than all of the sets of information received at the file list scanner module input.

2. The apparatus of claim 1 wherein the file list scanner identifies the sets of information in reverse chronological order.

3. The apparatus of claim 1, additionally comprising:

a first addressable storage coupled between the file list builder module output and the file list sorter module input for storing the sets of information received at an input coupled to the file list builder module output and providing at least one of the sets of information at an output coupled to the file list scanner module input; and

wherein;

each of the sets of information stored in the file list storage comprise a second identifier; and

the file list scanner module comprises;

a first file list scanner module storage having an input/output, for storing and providing at the input/output a third identifier received at the input/output; and

a next file identifier module having an input coupled to the file list scanner module input and an input/output coupled to the first file list scanner module storage input/output, for selecting and providing at a first output coupled to the file list scanner module output at least a portion of one of the sets of information having a second identifier less than the third identifier.

4. The apparatus of claim 3, wherein the next file identifier module comprises:

list scanner module, and the next file identifier module is additionally for providing at the next file identifier module second output a type indicator of each of the sets of information provided at the next file identifier module first output;

a second input coupled to a file list scanner module second input operatively coupled to receive a signal having a first state and a second state; and

wherein the next file identifier module selects and provides a set of information responsive to the signal received at the second next file identifier module input in the first state; and

the apparatus additionally comprises a last file identifier module having an input coupled to the file list scanner module second output, for providing at a first output coupled to the next file identifier module second input the signal responsive to the type identifier received at the last file identifier module input.

5. The apparatus of claim 4 wherein:

the file list scanner module additionally comprises a file list sorter module coupled to the file list storage for sorting the sets of identifiers in the file list storage in an order of a fourth identifier and breaking ties in an order of the second identifier.

6. The apparatus of claim 5 wherein the file list sorter module additionally breaks ties in favor of a type identifier corresponding to a datafile copy.

7. The apparatus of claim 6, additionally comprising:

a restore list stack having a first input coupled to the next file identifier module first output for receiving and storing at least one of the portions of the sets of information, and a second input coupled to the last file identifier module first output, the restore list stack for providing at an output coupled to the apparatus output a plurality of the portions of the sets of information stored.

8. The apparatus of claim 7 additionally comprising:

a next reset stamp identifier module having a first input operatively coupled to receive the first identifier, the next reset stamp identifier module for selecting a fifth identifier from a plurality of identifiers, the fifth identifier corresponding to at least one file stored before the at least one file corresponding to the first identifier, the next reset stamp identifier module additionally for providing to an output coupled to the file list builder module second input the fifth identifier.

9. The apparatus of claim 8 wherein the next file identifier module is additionally for comparing the fourth identifier of the set of information it selects with the third identifier stored in the input/output and for generating and providing at the first input/output a set of information responsive to the fourth identifier less than one less than the third identifier.

10. A method of identifying at least one backup file to restore, each file having a record, comprising:

receiving at least one first identifier corresponding to a first plurality of backup files comprising at least one file not containing errors; and

identifying the records of the first plurality of backup files corresponding to the at least one first identifier received from records of a second plurality of backup files comprising the first plurality of backup files and at least one additional backup file responsive to the receiving step.

11. The method of claim 10 wherein the identifying step is performed in a reverse chronological order indicated by the file records.

12. The method of claim 10, wherein each of the file records comprise a second identifier and a third identifier, and the identifying step comprises:

selecting a first file record;

comparing the second identifier of a first file record with the second identifier of a second file record;

comparing the third identifier of the first file record with the second identifier of the second file record; and

identifying the first file responsive to;

the second identifier of the first file having a value less than a value of the second identifier of the second file; and

a value of the third identifier of the first file not less than one less than the second identifier of the second file record.

13. The method of claim 12 wherein

the identifying step additionally comprises comparing the value of the second identifier of the first file with a value of the second identifier of a third file;

and

the identifying the first file is additionally responsive to the value of the second identifier of the first file not greater than the value of the second identifier of the third file.

14. The method of claim 12 wherein:

at least a plurality of each of the file records identified comprise a type having a first state and a second state;

the identifying step additionally comprises comparing the type of a second file record with the type of a third file record; and

the identifying the first file is additionally responsive to the type of the first file matching a value.

15. The method of claim 14 wherein the value corresponds to a value of a datafile copy.

16. The method of claim 12 wherein the identifying step additionally comprises:

designating the first file as the second file;

selecting another file as the first file; and

repeating the comparing steps and the identifying the first file step.

17. The method of claim 12 wherein the selecting the first file record step comprises:

selecting a first file;

comparing a value of the third identifier of the first file with a value of the first identifier of a second file; and

responsive to the value of the third identifier of the first file lower than one less than the value of the second identifier of the second file, generating a file record responsive to the third identifier of the first file and the second identifier of the second file.

18. The method of claim 10, comprising the additional steps of:

storing at least a portion of a plurality of the records identified in a first order; and

transmitting at least a portion of a plurality of the records stored in a second order different from the first order.

19. The method of claim 10, comprising the additional steps of:

receiving a fourth identifier corresponding to a third plurality of backup files; and

identifying in reverse chronological order records of the third plurality of backup files from records of a fourth plurality of backup files comprising the third plurality of backup files and at least one additional backup file.

20. A computer program product comprising a computer useable medium having computer readable program code embodied therein for identifying a plurality of backup files to restore, each such file having a record, the computer program product comprising:

computer readable program code devices configured to cause a computer to receive at least one first identifier corresponding to a first plurality of backup files comprising at least one file not containing errors; and

computer readable program code devices configured to cause a computer to identify the records of the first plurality of backup files corresponding to the at least one first identifier received from records of a second plurality of backup files comprising the first plurality of backup files and at least one additional backup file responsive to receipt of the at least one first identifier.

21. The computer program product of claim 20 wherein the computer readable program code devices configured to cause a computer to identify comprise computer readable program code devices configured to cause a computer to identify the records of the first plurality of backup file in a reverse chronological order indicated by the file records.

22. The computer program product of claim 20, wherein each of the file records comprise a second identifier and a third identifier, and the computer readable program code devices configured to cause a computer to identify comprise:

computer readable program code devices configured to cause a computer to select a first file record;

computer readable program code devices configured to cause a computer to compare the second identifier of a first file record with the second identifier of a second file record;

computer readable program code devices configured to cause a computer to compare the third identifier of the first file record with the second identifier of the second file record; and

computer readable program code devices configured to cause a computer to identify the first file responsive to;

the second identifier of the first file having a value less than a value of the second identifier of the second file; and

a value of the third identifier of the first file not less than one less than the second identifier of the second file record.

23. The computer program product of claim 22 wherein

the computer readable program code devices configured to cause a computer to identify additionally comprise computer readable program code devices configured to cause a computer to compare the value of the second identifier of the first file with a value of the second identifier of a third file;

and

the computer readable program code devices configured to cause a computer to identify the first file are additionally responsive to the value of the second identifier of the first file not greater than the value of the second identifier of the third file.

24. The computer program product of claim 22 wherein:

at least a plurality of each of the file records identified comprise a type having a first state and a second state;

the computer readable program code devices configured to cause a computer to identify additionally comprises computer readable program code devices configured to cause a computer to compare the type of a second file record with the type of a third file record; and

the computer readable program code devices configured to cause a computer to identify the first file are additionally responsive to the type of the first file matching a value.

25. The computer program product of claim 24 wherein the value corresponds to a value of a datafile copy.

26. The computer program product of claim 22 wherein the computer readable program code devices configured to cause a computer to identify additionally comprise:

computer readable program code devices configured to cause a computer to designate the first file as the second file;

computer readable program code devices configured to cause a computer to select another file as the first file; and

computer readable program code devices configured to cause a computer to repeat the comparing steps and the identifying the first file step.

27. The computer program product of claim 22 wherein the computer readable program code devices configured to cause a computer to select the first file record comprise:

computer readable program code devices configured to cause a computer to select a first file;

computer readable program code devices configured to cause a computer to compare a value of the third identifier of the first file with a value of the first identifier of a second file; and

computer readable program code devices configured to cause a computer to, responsive to the value of the third identifier of the first file lower than one less than the value of the second identifier of the second file, generate a file record responsive to the third identifier of the first file and the second identifier of the second file.

28. The computer program product of claim 20, additionally comprising:

computer readable program code devices configured to cause a computer to store at least a portion of a plurality of the records identified in a first order; and

computer readable program code devices configured to cause a computer to transmit at least a portion of a plurality of the records stored in a second order different from the first order.

29. The computer program product of claim 20, additionally comprising:

computer readable program code devices configured to cause a computer to receive a fourth identifier corresponding to a third plurality of backup files; and

computer readable program code devices configured to cause a computer to identify in reverse chronological order records of the third plurality of backup files from records of a fourth plurality of backup files comprising the third plurality of backup files and at least one additional backup file.