Listing data objects using a hierarchical dispersed storage index

1. A method for execution by a processing module of a computer, the method comprises:

receiving, via an interface of the computer, a request for a data index list that identifies data objects having one or more common attributes of an attribute category, wherein indexing of a plurality of data objects is organized in accordance with an ordering of attributes of the attribute category and wherein the plurality of data objects is stored in a dispersed storage network (DSN);

identifying, by the processing module, a first data object boundary match by identifying a first one of a plurality of index keys associated with the data object level index node that includes an indication that substantially matches the one or more common attributes, wherein the plurality of index keys are sequentially ordered in accordance with indicators corresponding to attributes of the attribute category;

searching, by the processing module, a hierarchical ordered index structure to identify a data object level index node that includes a first boundary data object index key corresponding to the first data object boundary match, wherein the searching is based on the one or more common attributes of an attribute category;

determining, by the processing module, whether the data object level index node includes a second boundary data object index key corresponding to a second data object boundary match of the one or more common attributes;

when the data object level index node does not include the second boundary data object index key, searching, by the processing module, an adjacent data object level index node of the hierarchical ordered index structure to determine whether the adjacent data object level index node includes the second boundary data object index key;

when the adjacent data object level index node includes the second boundary data object index key, generating, by the processing module, the data index list to include the first boundary data object index key, a first ordered set of data object index keys of the data object level index node, the second boundary data object index key, and a second ordered set of data object index keys of the adjacent data object level index node;

outputting, via the interface, the data index list;

receiving, via the interface, a read request for a data object identified in the data index list, wherein a data object is dispersed error encoded to generate a plurality of sets of encoded data slices;

identifying a set of DSN servers storing the plurality of sets of encoded data slices; and

sending a set of read requests to the set of DSN servers.

2. The method of claim 1 , wherein the generating the data index list further comprises:

determining DSN addresses corresponding to data object index keys of the data index list; and

adding the DSN addresses to the data index list.

3. The method of claim 1 further comprises:

receiving, via the interface, a read request regarding a data object identified in the data index list;

determining, by the processing module, a DSN address for the data object;

identifying, by the processing module, a set of dispersed storage (DS) servers based on the DSN address; and

sending, via the interface, a set of read requests to the set of DS servers to retrieve a set of data slices, wherein a data segment of the data object is stored as the set of data slices in the set of DS servers.

4. The method of claim 1 , wherein the searching the hierarchical ordered index structure comprises:

identifying a category index node based on the request;

retrieving, via the interface, a set of category index slices from the DSN;

reconstructing a category index file from the set of category index slices;

interpreting the category index file based on the one or more common attributes to identify a next level index node; and

when the next level index node is not the data object level index node, entering a loop that includes:

retrieving, via the interface, a set of next level index slices from the DSN;

reconstructing a next index file from the set of next level index slices;

interpreting the next index file based on the one or more common attributes to identify a new next level index node;

determining whether the new next level index node is the data object level index node;

when the new next level index node is the data object level index node, exiting the loop; and

when the new next level index node is not the data object level index node, repeating the loop with the new next level index node as the next level index node.

5. The method of claim 1 further comprises:

when the data object level index node includes the second boundary data object index key, generating, by the processing module, the data index list to include the first boundary data object index key, the second boundary data object index key, and an ordered set of data object index keys between the first and second boundary data object index keys.

6. The method of claim 1 further comprises:

when the adjacent data object level index node does not include the second boundary data object index key, entering a loop that includes:

searching, by the processing module, a next adjacent data object level index node of the hierarchical ordered index structure to determine whether the next adjacent data object level index node includes the second boundary data object index key;

when the next adjacent data object level index node includes the second boundary data object index key, exiting the loop and generating, by the processing module, the data index list; and

when the next adjacent data object level index node does not include the second boundary data object index key, repeating the loop using a second next adjacent data object level index node as the next adjacent data object level index node.

7. The method of claim 1 , wherein the indexing of the plurality of data objects comprises:

a corresponding plurality of data object index keys that is ordered in accordance with the ordering of attributes of the attribute category, wherein a data object index key of the plurality of corresponding data object index keys uniquely identifies one of the plurality of data objects in accordance with the attribute category.

8. A dispersed storage (DS) module of a computing device, the DS module comprises:

a first module, when operable within the computing device, causes the computing device to:

receive, via an interface of the computing device, a request for a data index list that identifies data objects having one or more common attributes of an attribute category, wherein indexing of a plurality of data objects is organized in accordance with an ordering of attributes of the attribute category and wherein the plurality of data objects is stored in a dispersed storage network (DSN);

a second module, when operable within the computing device, causes the computing device to:

identify, by the processing module, a first data object boundary match by identifying a first one of a plurality of index keys associated with the data object level index node that includes an indication that substantially matches the one or more common attributes, wherein the plurality of index keys are sequentially ordered in accordance with indicators corresponding to attributes of the attribute category;

a third module, when operable within the computing device, causes the computing device to:

search, a hierarchical ordered index structure to identify a data object level index node that includes a first boundary data object index key corresponding to the first data object boundary match, wherein the searching is based on the one or more common attributes of an attribute category;

determine whether the data object level index node includes a second boundary data object index key corresponding to a second data object boundary match of the one or more common attributes; and

when the data object level index node does not include the second boundary data object index key, search an adjacent data object level index node of the hierarchical ordered index structure to determine whether the adjacent data object level index node includes the second boundary data object index key; and

a fourth module, when operable within the computing device, causes the computing device to:

when the adjacent data object level index node includes the second boundary data object index key, generate the data index list to include the first boundary data object index key, a first ordered set of data object index keys of the data object level index node, the second boundary data object index key, and a second ordered set of data object index keys of the adjacent data object level index node;

output, via the interface, the data index list;

receive, via the interface, a read request for a data object identified in the data index list, wherein a data object is dispersed error encoded to generate a plurality of sets of encoded data slices;

identify a set of DSN servers storing the plurality of sets of encoded data slices; and

sending a set of read requests to the set of DSN servers.

9. The DS module of claim 8 , wherein the third module further functions to generate the data index list by:

determining DSN addresses corresponding to data object index keys of the data index list; and

adding the DSN addresses to the data index list.

10. The DS module of claim 8 further comprises:

a fifth module, when operable within the computing device, causes the computing device to:

receive, via the interface, a read request regarding a data object identified in the data index list;

determine a DSN address for the data object;

identify a set of dispersed storage (DS) servers based on the DSN address; and

send, via the interface, a set of read requests to the set of DS servers to retrieve a set of data slices, wherein a data segment of the data object is stored as the set of data slices in the set of DS servers.

11. The DS module of claim 8 , wherein the second module functions to search the hierarchical ordered index structure by:

identifying a category index node based on the request;

retrieving a set of category index slices from the DSN;

reconstructing a category index file from the set of category index slices;

interpreting the category index file based on the one or more common attributes to identify a next level index node; and

when the next level index node is not the data object level index node, entering a loop that includes:

retrieving a set of next level index slices from the DSN;

reconstructing a next index file from the set of next level index slices;

interpreting the next index file based on the one or more common attributes to identify a new next level index node;

determining whether the new next level index node is the data object level index node;

when the new next level index node is the data object level index node, exiting the loop; and

when the new next level index node is not the data object level index node, repeating the loop with the new next level index node as the next level index node.

12. The DS module of claim 8 further comprises:

the fourth module further functions to:

when the data object level index node includes the second boundary data object index key, generate the data index list to include the first boundary data object index key, the second boundary data object index key, and an ordered set of data object index keys between the first and second boundary data object index keys.

13. The DS module of claim 8 further comprises:

the third module further functions to:

when the adjacent data object level index node does not include the second boundary data object index key, enter a loop to:

search a next adjacent data object level index node of the hierarchical ordered index structure to determine whether the next adjacent data object level index node includes the second boundary data object index key;

when the next adjacent data object level index node includes the second boundary data object index key, exit the loop and generate the data index list; and

when the next adjacent data object level index node does not include the second boundary data object index key, repeat the loop using a second next adjacent data object level index node as the next adjacent data object level index node.

14. The DS module of claim 8 , wherein the indexing of the plurality of data objects comprises:

a corresponding plurality of data object index keys that is ordered in accordance with the ordering of attributes of the attribute category, wherein a data object index key of the plurality of corresponding data object index keys uniquely identifies one of the plurality of data objects in accordance with the attribute category.