Limitations of SPARQL explain in Neptune
The release of the Neptune SPARQL explain feature has the
following limitations.
Neptune Currently Supports Explain Only in SPARQL SELECT Queries
For information about the evaluation process for other query forms, such as
ASK, CONSTRUCT, DESCRIBE, and SPARQL
UPDATE queries, you can transform these queries into a SELECT query. Then use
explain to inspect the corresponding SELECT query instead.
For example, to obtain explain information about an
ASK WHERE {...} query, run the corresponding
SELECT WHERE {...} LIMIT 1 query with explain.
Similarly, for a CONSTRUCT {...} WHERE {...} query, drop the
CONSTRUCT {...} part and run a SELECT query with
explain on the second WHERE {...} clause. Evaluating
the second WHERE clause generally reveals the main challenges of
processing the CONSTRUCT query, because solutions flowing out of
the second WHERE into the CONSTRUCT template generally
only require straightforward substitution.
Explain Operators May Change in Future Releases
The SPARQL explain operators and their parameters may change
in future releases.
Explain Output May Change in Future Releases
For example, column headers could change, and more columns might be added to the tables.