Processing path-based database operations

• US 20060117049A1
• Filed: 11/29/2004
• Published: 06/01/2006
• Est. Priority Date: 11/29/2004
• Status: Active Grant

• Current Assignee: Oracle International Corporation (Oracle Corporation)
• Original Assignee: Oracle International Corporation (Oracle Corporation)
• Inventors: Sedlar, Eric, Jain, Namit, Murthy, Ravi, Agarwal, Nipun, Muralidhar, Subramanian, Ge, Fei
• Granted Patent: US 7,627,547 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 16/13 File access structures, e.g. distributed indices arrangements of input from, or output to, record carriers G06F3/06
• CPC Class Codes: G06F 16/188 Virtual file systems
• CPC Class Codes: Y10S 707/99931 Database or file accessing

Abstract

A method and apparatus for processing path-based database operations is provided. According to one aspect, a “parent row ID” column is added to a directory links table. For each row in the table, the value of the “parent row ID” column indicates the row ID, in the table, of the node that is that row'"'"'s node'"'"'s parent in the file hierarchy. To determine whether a particular node is within a specified path of the file hierarchy, the particular node'"'"'s pathname is derived by visiting child-to-parent links indicated in the table and prepending, to the front of a pathname being constructed for the particular node, node names indicated in the visited rows. Each parent node'"'"'s row in the directory links table is located using the “parent row ID” column of the child node'"'"'s row. The resulting pathname is compared with the specified path to determine whether the particular node exists therein.

Claims

1. A method of processing path-based database operations, the method comprising:

locating a first database table row that is associated with a first node in a hierarchy, wherein the first database table row is located at a storage location that corresponds to a first row identifier, and wherein the first database table row includes a second row identifier that indicates a storage location of a second database table row that is associated with a second node that is a parent of the first node in the hierarchy; and

prepending, to the front of a path name that is being formed for the first node, a node name that is indicated in the second database table row.

2. The method of claim 1, wherein the second database table row includes a third row identifier that indicates a storage location of a third database table row that is associated with a third node that is a parent of the second node in the hierarchy.

3. The method of claim 2, further comprising:

prepending, to the front of the path name, a node name that is indicated in the third database table row.

4. The method of claim 1, further comprising:

determining, based on the path name, whether the first node is in a specified path of the hierarchy.

5. The method of claim 1, wherein locating the first database table row is performed in response to receiving a request to determine whether the first node is in a specified path of the hierarchy.

6. The method of claim 5, further comprising:

determining whether an entity from which the request was received is associated with a security level that is less than a security level that is indicated by the second database table row; and

in response to a determination that the entity from which the request was received is associated with a security level that is less than the security level that is indicated by the second database table row, generating an indication that the entity is not allowed to determine whether the first node is in the specified path.

7. The method of claim 1, further comprising:

determining whether a path that contains the second node is contained in a cache; and

in response to a determination that the path is contained in the cache, prepending, to the front of the path name, a string that corresponds to the path.

9. A computer-readable medium carrying one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 1.

10. A computer-readable medium carrying one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 2.

11. A computer-readable medium carrying one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 3.

12. A computer-readable medium carrying one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 4.

13. A computer-readable medium carrying one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 5.

14. A computer-readable medium carrying one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 6.

15. A computer-readable medium carrying one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 7.

8. A method of constructing a path name for an item that belongs to a hierarchy, the method comprising:

performing a bottom-up traversal of an index built on items that belong to the hierarchy;

wherein the traversal begins at an index entry associated with said item, and follows child-to-parent links between index entries; and

wherein the path name for the item is constructed based on item names associated with the index entries visited during said traversal.

16. A computer-readable medium carrying one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 8.