Basic (s)-[p]->(o) query is not working when there is an RDFGraph in the db (hashtag2734)

[vikramsubramanian]

kuzu> MATCH (s)-[p]->(o) RETURN count(*);
Error: Binder exception: Relationship pattern p with multiple rdf table labels is not supported.

We should be able to handle this.

)

[mayil-ai[bot]]

Summary: Error occurs when running a basic query with RDFGraph in the database.

Possible Solution

Based on the provided information, the issue seems to be related to the handling of relationship patterns with multiple RDF table labels in the query engine. The error message indicates that the system does not support such patterns. To resolve the issue, follow these steps:

• Locate the code responsible for handling relationship patterns in the query engine, specifically in the src/binder/bind/bind_graph_pattern.cpp file.
• Modify the bind_graph_pattern.cpp to allow handling of relationship patterns with multiple RDF table labels. This could involve updating the logic that throws the BinderException when resourceTableIDs.size() > 1.
• Ensure that the query engine can correctly interpret and process relationship patterns that involve multiple RDF table labels. This may require additional logic to handle joins or other operations across multiple RDF tables.
• Add or update unit tests to cover the new functionality and ensure that relationship patterns with multiple RDF table labels are handled correctly.
• Test the changes thoroughly to ensure that the issue is resolved and that no new issues have been introduced.

Here is a potential code change in src/binder/bind/bind_graph_pattern.cpp:

if (!resourceTableIDs.empty()) {
    // Allow handling of multiple RDF table labels by implementing the required logic
    // For example, create a join operation across the multiple RDF tables
    // The following is a placeholder for the actual implementation
    auto joinOperation = createJoinOperationAcrossMultipleTables(resourceTableIDs);
    queryRel->setJoinOperation(std::move(joinOperation));
    // Rest of the code remains unchanged
}
return queryRel;

Please note that the above code snippet is a high-level example and does not contain the actual implementation details. The actual implementation would depend on the specific requirements and architecture of the Kùzu graph database.

Code snippets to check

• src/binder/bind/bind_graph_pattern.cpp

  The error message in the issue matches the one thrown in this snippet, indicating that the issue is likely related to the handling of relationship patterns with multiple RDF table labels.