Multilabel relationship pattern not working when a db has more than 1 RDFGraph (hashtag2769)

[vikramsubramanian]

I have 2 RDFGraphs in my database: TurtleEx and UniKG. The following gives a binder error:

kuzu> MATCH (a:UniKG_r {iri: " RETURN *;
Error: Binder exception: Relationship pattern p with multiple rdf table labels is not supported.

If I drop TurtleEx, then the query works as expected. I don't think there is a good reason the above query is not supported. )

[mayil-ai[bot]]

Summary: Relationship pattern with multiple RDFGraph labels is not supported in the database, causing a binder error.

Possible Solution

Based on the provided information, the issue seems to be related to a query that attempts to match a relationship pattern with multiple RDF table labels, which is not supported by the system. The relevant code snippet that throws the exception is found in src/binder/bind/bind_graph_pattern.cpp.

To resolve the issue, you should:

• Ensure that the query does not attempt to match a relationship pattern (MATCH clause) with multiple RDF table labels. This could mean modifying the query to only match patterns with a single RDF table label.
• If the query is intended to work with multiple RDF table labels, you may need to refactor the underlying code to support such queries, which could be a significant change depending on the system's architecture and design.

If the former is the case and the query needs to be modified, here's what you should do:

• Identify the query that is causing the issue. It should be a MATCH clause that includes a relationship pattern with a node labeled UniKG_r and a property iri.
• Modify the query to ensure that each relationship pattern only involves one RDF table label.
• Test the modified query to ensure that it no longer triggers the BinderException.

If the latter is the case and the system needs to support multiple RDF table labels in a single relationship pattern, here's a high-level approach:

• Update the bindGraphPattern and related functions in src/binder/bind/bind_graph_pattern.cpp to handle multiple RDF table labels.
• This might involve changing the logic that checks the resourceTableIDs.size() and throws the BinderException.
• Ensure that the rest of the system can handle the implications of this change, including query execution and result processing.
• Thoroughly test the updated system to ensure that it behaves correctly with the new functionality.

Code snippets to check

• src/binder/bind/bind_graph_pattern.cpp

  This snippet contains the logic that throws the 'BinderException' when a relationship pattern with multiple RDF table labels is encountered, which is directly related to the issue described.