Method for duplicate determination in a graph

1. A computer-implemented method comprising:

determining duplicates in a graph wherein the graph comprises nodes representing entities and edges that represent relationships between the entities by:

identifying at least two nodes in the graph, wherein identifying at least two nodes in the graph comprises:

calculating an index structure,

grouping the index structure according to edge descriptors of individual index entries, resulting in a set of one or more groups,

selecting a first node of the at least two nodes, and

finding further nodes that are in a same group, of the set of groups, as the first node;

determining a respective neighborhood subgraph for each of the two nodes, the neighborhood subgraph including a respective node;

comparing the respective neighborhood subgraphs; and

determining whether the two nodes are duplicates with respect to each other, based on a result of the comparison.

2. The computer-implemented method of claim 1 , wherein determining of the neighborhood subgraph of the node comprises:

selecting nodes of the graph using a selection criterion, the selection criterion being based on at least one of: a number of nodes, an entity represented by a node, a distance between the node and another node in the subgraph; the subgraph comprising the selected nodes.

3. The computer-implemented method of claim 2 , wherein the selection criterion requires at least one of:

the number of nodes of the subgraph being smaller than a maximum number;

the edge of the subgraph connected to at least one node that represents a same entity as the entity of the node; and

the distance between the node and another node in the subgraph is smaller than a threshold number of edges.

4. The computer-implemented method of claim 1 , wherein comparing the respective subgraphs comprises:

calculating a similarity metric;

comparing the calculated similarity metric with a predefined threshold; and

in response to determining that the similarity metric exceeds the predefined threshold determining whether the two nodes are duplicates.

5. The computer-implemented method of claim 1 , further comprising:

in response to determining that the two nodes are duplicates, performing a twin detection method, wherein the twin detection method comprises:

acquiring additional properties of the entities represented by the two nodes; and

cancelling a decision that the two nodes are duplicates with respect to each other based on the additional properties.

6. The computer-implemented method of claim 1 , wherein the index structure comprises:

for each node of the graph, at least one index entry, the index entry including an identifier of the node and an edge descriptor describing an edge connected to that node, wherein the edge descriptor comprises direction information related to a direction of the edge and/or a neighbor node identifier.

7. The computer-implemented method of claim 6 , wherein the individual index entries are represented as text strings.

8. The computer-implemented method of claim 6 , wherein the grouping further comprises deleting groups based on their size.

9. The computer-implemented method of claim 1 , wherein determining of the neighborhood subgraphs comprises:

removing duplicate nodes of each subgraph in the neighborhood subgraphs.

10. The computer-implemented method of claim 1 , further comprising:

using a received indication of the two identified nodes for the identifying.

11. A computer program product comprising:

one or more computer readable storage media and program instructions stored on the one or more computer readable storage media, the program instructions comprising:

program instructions to determine duplicates in a graph wherein the graph comprises nodes representing entities and edges that represent relationships between the entities by:

program instructions to identify at least two nodes in the graph, wherein the program instructions to identify at least two nodes in the graph comprises:

program instructions to calculate an index structure,

program instructions to group the index structure according to edge descriptors of individual index entries, resulting in a set of one or more groups,

program instructions to select a first node of the at least two nodes, and

program instructions to find further nodes that are in a same group, of the set of groups, as the first node;

program instructions to determine a neighborhood subgraph for each of the two nodes, the neighborhood subgraph including a respective node;

program instructions to compare the respective neighborhood subgraphs; and

program instructions to determine whether the two nodes are duplicates with respect to each other, based on a result of the comparison.

12. The computer program product of claim 11 , wherein the program instructions to determine of the neighborhood subgraph of the node comprise:

program instructions to select nodes of the graph using a selection criterion, the selection criterion being based on at least one of: a number of nodes, an entity represented by a node, a distance between the node and another node in the subgraph; the subgraph comprising the selected nodes.

13. The computer program product of claim 12 , wherein the selection criterion requires at least one of:

the number of nodes of the subgraph being smaller than a maximum number;

the edge of the subgraph connected to at least one node that represents a same entity as the entity of the node; and

the distance between the node and another node in the subgraph is smaller than a threshold number of edges.

14. The computer program product of claim 11 , wherein the program instructions to compare the respective subgraphs comprise:

program instructions to calculate a similarity metric;

program instructions to compare the calculated similarity metric with a predefined threshold; and

program instructions to, in response to determining that the similarity metric exceeds the predefined threshold, determine whether the two nodes are duplicates.

15. The computer program product of claim 11 , wherein the program instructions stored on the one or more computer readable storage media further comprise:

program instructions to, in response to determining that the two nodes are duplicates, perform a twin detection method, wherein the twin detection method comprises:

program instructions to acquire additional properties of the entities represented by the two nodes; and

program instructions to cancel a decision that the two nodes are duplicates with respect to each other based on the additional properties.

16. A computer system comprising:

one or more computer processors;

one or more computer readable storage media; and

program instructions stored on the one or more computer readable storage media for execution by at least one of the one or more computer processors, the program instructions comprising:

program instructions to determine duplicates in a graph wherein the graph comprises nodes representing entities and edges that represent relationships between the entities by:

program instructions to identify at least two nodes in the graph, wherein the program instructions to identify at least two nodes in the graph comprises:

program instructions to calculate an index structure,

program instructions to group the index structure according to edge descriptors of individual index entries, resulting in a set of one or more groups,

program instructions to select a first node of the at least two nodes, and

program instructions to find further nodes that are in a same group, of the set of groups, as the first node;

program instructions to determine a neighborhood subgraph for each of the two nodes, the neighborhood subgraph including a respective node;

program instructions to compare the respective neighborhood subgraphs; and

program instructions to determine whether the two nodes are duplicates with respect to each other, based on a result of the comparison.

17. The computer system of claim 16 , wherein the program instructions to determine of the neighborhood subgraph of the node comprise:

program instructions to select nodes of the graph using a selection criterion, the selection criterion being based on at least one of: a number of nodes, an entity represented by a node, a distance between the node and another node in the subgraph; the subgraph comprising the selected nodes.

18. The computer system of claim 17 , wherein the selection criterion requires at least one of:

the number of nodes of the subgraph being smaller than a maximum number;

the edge of the subgraph connected to at least one node that represents a same entity as the entity of the node; and

the distance between the node and another node in the subgraph is smaller than a threshold number of edges.

19. The computer system of claim 16 , wherein the program instructions to compare the respective subgraphs comprise:

program instructions to calculate a similarity metric;

program instructions to compare the calculated similarity metric with a predefined threshold; and

program instructions to, in response to determining that the similarity metric exceeds the predefined threshold, determine whether the two nodes are duplicates.

20. The computer system of claim 16 , wherein the program instructions stored on the one or more computer readable storage media further comprise:

program instructions to, in response to determining that the two nodes are duplicates, perform a twin detection method, wherein the twin detection method comprises:

program instructions to acquire additional properties of the entities represented by the two nodes; and

program instructions to cancel a decision that the two nodes are duplicates with respect to each other based on the additional properties.